Molecular targets and compounds, and methods to identify the same, useful in the treatment of fibrotic diseases

ABSTRACT

The present invention relates to methods and assays for identifying agents useful in the treatment of fibrotic conditions. The invention provides polypeptide and nucleic acid TARGETs, siRNA sequences based on these TARGETs and antibodies against the TARGETs. The invention is further related to pharmaceutical composition comprising siRNA sequences based on the TARGETs and antibodies against the TARGETs for use in the treatment of fibrotic conditions. The invention further provides in vitro methods for reduction or inhibition of macrophage differentiation into alternatively-activated macrophages (M2).

TECHNICAL FIELD OF THE INVENTION

The present invention is in the field of molecular biology and biochemistry. The present invention relates to methods for identifying agents useful in treatment of fibrotic disease, in particular, agents that reduce or inhibit macrophage differentiation into the alternatively-activated (M2) phenotype. Reduction or inhibition of differentiation into the alternatively-activated (M2) phenotype is useful in the prevention and/or treatment of fibrotic conditions and other diseases where alternatively-activated (M2) macrophages play a role. In particular, the present invention provides methods for identifying agents for use in the prevention and/or treatment of fibrotic diseases.

BACKGROUND OF THE INVENTION

Fibrosis is characterized by excessive deposition of scar tissue by fibroblasts and it is currently one of the largest groups of diseases for which there is no therapy. Fibrosis is responsible for morbidity and mortality associated with organ failure in a variety of chronic diseases affecting the lungs, heart, kidneys, liver and skin. It has been estimated that nearly 45% of all deaths in the developed world are caused by or related to fibrotic conditions which include: cardiovascular disease, pulmonary fibrosis, diabetic nephropathy and liver cirrhosis (Wynn et. al., 2004).

Fibrosis and, especially, idiopathic pulmonary fibrosis (IPF) is a disease that is receiving increasing attention. The pathogenesis of fibrosis has been relatively undefined and only recently the various cellular and molecular processes that contribute to this disease have been unveiled. The overall consensus is that fibrosis is a result of an imbalance in the immune and repair response following infection and/or tissue damage (reviewed by Lekkerkerker et al 2012). These responses are the result of an intricate interplay between various cell types such as epithelial cells, fibroblasts, macrophages, fibrocytes, smooth muscle cells and endothelial cells. An imbalance in the activity in one or more of these cell types is expected to contribute to fibrosis.

Macrophages are responsible for immune surveillance and tissue homeostasis. They are able to engulf pathogens using a broad repertoire of pathogen recognition receptors (PRRs) and destroy them via degradation within lysosomes. Within the process of tissue homeostasis, macrophages play an essential role in removing dead and dying cells and toxic materials. Furthermore, macrophages are crucial in the orchestration of the wound healing process. To perform these important functions, macrophages consist of different subpopulations which are strategically positioned throughout the body (Mantovani et al., 2004).

During an immune response, monocytes are recruited from the circulation in the tissues and differentiate into macrophages. Following tissue damage and/or infection, macrophages exhibit primarily a pro-inflammatory phenotype and secrete pro-inflammatory mediators such as TNFα and IL-1. These pro-inflammatory macrophages are often called classically activated macrophages or M1 macrophages. Various chronic inflammatory disease and autoimmune diseases, such as, for example, rheumatoid arthritis, are associated with activation of M1 macrophages (Murphy et al., 2003).

To prevent an exacerbated immune response and collateral damage to surrounding tissue the M1 macrophage response needs to be tightly controlled. Macrophages that play a role in wound healing have been designated as alternatively-activated macrophages or, otherwise, M2 macrophages. This subset of macrophages secretes anti-inflammatory mediators and is strongly associated with Th2 mediated inflammation and antagonizes M1 macrophages to regulate the immune response.

A major initiator of fibrosis is the persistence of exogenous and endogenous stimuli of pathogens or tissue injury (Meneghin et aL, 2007). Both classically activated (M1) and alternatively-activated (M2) macrophages are involved in the process of fibrosis. Nevertheless, M2 macrophages are considered to be the predominant macrophage subtype contributing to fibrosis (Song et al., 2000; Murray et al., 2011; Wynn, 2004). Furthermore, alveolar macrophages isolated from IPF patients are predominantly of a M2 macrophage phenotype (Thannickal et al., 2004).

A key characteristic of many fibrotic diseases is abnormal or exaggerated deposition of extracellular matrix degradation (ECM) (Cox et al, 2011). M2 macrophages can directly affect fibrosis by the excretion of pro-fibrotic mediators, such as tissue inhibitors of metalloproteinases and thereby directly inhibiting ECM turnover (Duffield et al., 2005). M2 macrophages also produce fibronectin, a key component of the ECM and thus contribute, directly to the buildup of excessive ECM. Besides the direct effect of M2 macrophages on fibrosis, M2 macrophages also indirectly contribute to fibrosis through activation of other cell types such as T cells, fibroblasts, and endothelial cells and thereby aggravating fibrosis (Wynn, 2008).

A hallmark of M2 macrophages is the production of CCL18, also known as pulmonary activation-related chemokine (PARC), and it is highly expressed in alveolar macrophages of IPF patients (Prasse et al., 2006, 2007, 2009). Other markers of M2 macrophages have been also identified, among them CD206 and CD163 (Mantovani et al, 2004). Prasse et al. showed that CCL18 concentration within the serum of idiopathic pulmonary fibrosis (IPF) patients strongly correlates with severity of IPF and is a predictive value for mortality (Prasse and Probst et al., 2009). In addition, CCL18 production is strongly increased in the lungs of patients with pulmonary fibrosis and affects cells such as fibroblasts, functioning directly as a pro-fibrotic factor (Atamas et al., 2003). Given that CCL18 is predominantly produced by M2 macrophages, it is likely that a misbalance between M1 and M2 macrophages favoring the M2 macrophages is involved in fibrosis. Recent studies have shown that M1 macrophages can convert into M2 macrophages indicating a dynamic balance between both macrophage subtypes (Duffield et al. 2005). Therefore, interfering in the M1/M2 balance, in particular preventing the occurrence of the M2 phenotype, provides a strategy to intervene in the process of fibrosis.

Over the past few decades much effort has been put into the development of in vitro and in vivo models to unravel the molecular mechanisms regulating fibrotic processes. Employment of primary cells and, preferably, those from fibrosis patients will provide us with better insights in the molecular processes involved in fibrotic disease. It is, however, important to use these cells under physiological conditions and in a disease-relevant context. The study of macrophages in functional assays relevant for fibrosis in combination with functional genomics can give invaluable insight into possible molecular mechanisms contributing to fibrosis and identify novel genetic targets for treatment of fibrosis. Therefore, there is a clear need to understand molecular and cellular processes related to fibrosis and to provide new methods of identifying targets, novel targets, and compounds useful for treatment of fibrosis.

SUMMARY OF THE INVENTION

The present invention is based on the discovery that agents that inhibit the expression and/or activity of the TARGETS disclosed herein are capable of reducing or inhibiting the differentiation of macrophages into alternatively-activated macrophages (M2 macrophages), as indicated by a inhibition of expression and/or release of markers of M2 macrophages, in particular a suppression of the release or expression of CCL18 and/or CD206. The present invention, therefore, provides TARGETS which play a role in the differentiation of macrophages into M2 macrophages, methods for screening for agents capable of down-regulating the expression and/or activity of TARGETS and the use of these agents in the prevention and/or treatment of fibrotic diseases, in particular diseases associated with alternatively-activated macrophages, by inhibiting the differentiation of macrophages into M2 macrophages. The present invention provides TARGETS which are involved in the formation and biology of M2 macrophages, in particular with fibrosis and fibrotic diseases. In a particular aspect, the present invention provides TARGETS which are involved in or otherwise associated with development of fibrosis.

The present invention relates to a method for identifying a compound useful for the treatment of fibrosis, said method comprising: contacting a test compound with a TARGET polypeptide, fragments and structurally functional derivatives thereof, determining a binding affinity of the test compound to said polypeptide or an activity of said polypeptide, contacting the test compound with a population of macrophage cells, measuring a property related to differentiation of macrophages into M2 macrophages, and identifying a compound capable of reducing or inhibiting macrophage differentiation into M2 macrophages and which either demonstrate a binding affinity to said polypeptide or are able to inhibit the activity of said polypeptide.

The present invention further relates to a method for identifying a compound useful for the treatment of fibrosis, said method comprising: contacting a test compound with population of macrophage cells and expressing a TARGET polypeptide, measuring expression and/or amount of said polypeptide in said cells, measuring a property related to differentiation of macrophages into M2 macrophages, and identifying a compound which reduces the expression and/or amount of said polypeptide and which is capable of reducing or inhibiting the differentiation of macrophages into M2 macrophages.

The present invention relates to a method for identifying a compound capable of reducing or inhibiting differentiation of macrophages into M2 macrophages said method comprising: contacting a test compound with a TARGET polypeptide, fragments or structurally functional derivatives thereof, determining a binding affinity of the test compound to said polypeptide or an activity of said polypeptide, contacting the test compound with a population of macrophage cells, measuring a property related to differentiation of macrophages into M2 macrophages, and identifying a compound capable of inhibiting macrophage differentiation into M2 macrophages and which demonstrates a binding affinity to said polypeptide and/or is able to inhibit the activity of said polypeptide.

The present invention provides a method for identifying a compound capable of reducing or inhibiting differentiation of macrophages into M2 macrophages said method comprising: contacting a test compound with a TARGET polypeptide, fragments or structurally functional derivatives thereof, determining a binding affinity of the test compound to said polypeptide or expression or an activity of said polypeptide, and identifying a compound capable of inhibiting macrophage differentiation into M2 macrophages as a compound which demonstrates a binding affinity to said polypeptide and/or is able to inhibit the expression or activity of said polypeptide.

The present invention also relates to:

-   -   a) pharmaceutical compositions comprising an antibody or a         fragment thereof which specifically binds to a TARGET         polypeptide, for use in the treatment of a fibrotic condition.     -   b) pharmaceutical compositions comprising an agent selected from         the group consisting of an antisense polynucleotide, a ribozyme,         a small interfering RNA (siRNA) and a short-hairpin RNA (shRNA)         for use in the treatment of a fibrotic condition, wherein said         agent comprises a nucleic acid sequence complementary to, or         engineered from, a naturally-occurring polynucleotide sequence         of about 17 to about 30 contiguous nucleotides of a nucleic acid         sequence selected encoding a TARGET polypeptide for use in the         treatment of a fibrotic condition.

Another aspect of this invention relates to an in vitro method of reducing or inhibiting the differentiation of macrophages into alternatively-activated (M2) macrophages, said method comprising contacting a population of macrophage cells with an inhibitor of the activity or expression of a TARGET polypeptide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the plate layout of the primary screen. Layout of the library plates with the negative control viruses (N1, N2, and N3) and the positive control viruses (P1, P2, P3, P4, and P5) in column 13 and 14. The remainder of the plate consisted of random viruses (Samples) from the Adenoviral library.

FIG. 2 depicts the primary screen set-up.

FIG. 3 shows B-score values for the individual controls and samples in primary screen. The graphs show the B-score of the negative controls (N1, N2, and N3), the positive controls (P1, P2, P3, P4, and P5) and the samples (S) for the complete screen (A) and the four separate analyzed plates (B). The dashed lines indicate the cut-off used for hit calling.

FIG. 4 shows rescreen plate layout. Layout of the library plates with the negative control viruses and the positive control viruses distributed over the plate. The remaining of the plate consisted of randomly distributed viruses which were identified as hits in the primary screen. The outer wells were not used.

FIG. 5 shows B-score values for the individual controls and samples in re-screen. The graphs show the B-score of the negative controls, the positive controls and the samples. The dashed lines indicate the cut-off used for hit calling.

FIG. 6 shows the experimental setup of the M1 counter screen.

FIG. 7 shows plate layout of the M1 counter screen. Layout of the 384-well plates with the negative control viruses (N1, N2, and N3), the TNF_v12 positive control viruses (P3), the other positive control viruses (P1 and P2) and the random viruses (Samples) from the adenoviral library. The outer wells were left empty.

FIG. 8 shows the schematic overview of the M2 validation screen.

FIG. 9 shows the M2 validation screen plate layout. Layout of the validation screen source plates containing the negative control viruses (N1, N2, and N3), the positive control viruses (P1, P2, P3, P4, P5, and P6), no virus wells and candidate Targets from the adenoviral library (the rest of the wells). The edges of the plates were left empty, except for the wells as indicated in column one in which various concentrations of stauroporin were added.

FIG. 10 shows the results of the M2 validation screen. The graphs represent the performance of the controls containing no virus and negative controls compared to positive controls in the CD206 screen (A) and the CTB screen (B). The hit calling cut-offs for the CD206 screen (−3) and for the CTB screen (−10) are indicated with the dashed lines. All values depicted are normalized data points using the Robust Z score.

DETAILED DESCRIPTION Definitions

The following terms are intended to have the meanings presented below and are useful in understanding the description and intended scope of the present invention.

The term ‘agent’ means any molecule, including polypeptides, polynucleotides, natural products and small molecules. In particular the term agent includes compounds such as test compounds or drug candidate compounds.

The term ‘activity inhibitory agent’ or ‘activity inhibiting agent’ means an agent, e.g. a polypeptide, small molecule, compound designed to interfere or capable of interfering selectively with the activity of a specific polypeptide or protein normally expressed within or by a cell.

The term ‘agonist’ refers to an agent that stimulates the receptor the agent binds to in the broadest sense.

As used herein, the term ‘antagonist’ is used to describe an agent that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses, or prevents or reduces agonist binding and, thereby, agonist-mediated responses.

The term ‘assay’ means any process used to measure a specific property of an agent, including a compound. A ‘screening assay’ means a process used to characterize or select compounds based upon their activity from a collection of compounds.

The term ‘binding affinity’ is a property that describes how strongly two or more compounds associate with each other in a non-covalent relationship. Binding affinities can be characterized qualitatively, (such as ‘strong’, ‘weak’, ‘high’, or low′) or quantitatively (such as measuring the KD).

The term ‘carrier’ means a non-toxic material used in the formulation of pharmaceutical compositions to provide a medium, bulk and/or useable form to a pharmaceutical composition. A carrier may comprise one or more of such materials such as an excipient, stabilizer, or an aqueous pH buffered solution. Examples of physiologically acceptable carriers include aqueous or solid buffer ingredients including phosphate, citrate, and other organic acids; antioxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptide; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as TWEEN®, polyethylene glycol (PEG), and PLURONICS®.

The term ‘complex’ means the entity created when two or more compounds bind to, contact, or associate with each other.

The term ‘compound’ is used herein in the context of a ‘test compound’ or a ‘drug candidate compound’ described in connection with the assays and methods of the present invention. As such, these compounds comprise organic or inorganic compounds, derived synthetically or from natural sources. The compounds include inorganic or organic compounds such as polynucleotides (e.g. siRNA or cDNA), lipids or hormone analogs. Other biopolymeric organic test compounds include peptides comprising from about 2 to about 40 amino acids and larger polypeptides comprising from about 40 to about 500 amino acids, including polypeptide ligands, enzymes, receptors, channels, antibodies or antibody conjugates.

The term ‘condition’ or ‘disease’ means the overt presentation of symptoms (i.e., illness) or the manifestation of abnormal clinical indicators (for example, biochemical or cellular indicators). Alternatively, the term ‘disease’ refers to a genetic or environmental risk of or propensity for developing such symptoms or abnormal clinical indicators.

The term ‘contact’ or ‘contacting’ means bringing at least two moieties together, whether in an in vitro system or an in vivo system.

The term ‘derivatives of a polypeptide’ relates to those peptides, oligopeptides, polypeptides, proteins and enzymes that comprise a stretch of contiguous amino acid residues of the polypeptide and that retain a biological activity of the protein, for example, polypeptides that have amino acid mutations compared to the amino acid sequence of a naturally-occurring form of the polypeptide. A derivative may further comprise additional naturally occurring, altered, glycosylated, acylated or non-naturally occurring amino acid residues compared to the amino acid sequence of a naturally occurring form of the polypeptide. It may also contain one or more non-amino acid substituents, or heterologous amino acid substituents, compared to the amino acid sequence of a naturally occurring form of the polypeptide, for example a reporter molecule or other ligand, covalently or non-covalently bound to the amino acid sequence.

The term ‘derivatives of a polynucleotide’ relates to DNA-molecules, RNA-molecules, and oligonucleotides that comprise a stretch of nucleic acid residues of the polynucleotide, for example, polynucleotides that may have nucleic acid mutations as compared to the nucleic acid sequence of a naturally occurring form of the polynucleotide. A derivative may further comprise nucleic acids with modified backbones such as PNA, polysiloxane, and 2′-O-(2-methoxy)ethyl-phosphorothioate, non-naturally occurring nucleic acid residues, or one or more nucleic acid substituents, such as methyl-, thio-, sulphate, benzoyl-, phenyl-, amino-, propyl-, chloro-, and methanocarbanucleosides, or a reporter molecule to facilitate its detection.

The term ‘endogenous’ shall mean a material that a mammal naturally produces. Endogenous in reference to the term ‘enzyme’, ‘protease’, ‘kinase’, or G-Protein Coupled Receptor (‘GPCR’) shall mean that which is naturally produced by a mammal (for example, and not by limitation, a human). In contrast, the term non-endogenous in this context shall mean that which is not naturally produced by a mammal (for example, and not by limitation, a human). Both terms can be utilized to describe both in vivo and in vitro systems. For example, and without limitation, in a screening approach, the endogenous or non-endogenous TARGET may be in reference to an in vitro screening system. As a further example and not limitation, where the genome of a mammal has been manipulated to include a non-endogenous TARGET, screening of a candidate compound by means of an in vivo system is feasible.

The term ‘expressible nucleic acid’ means a nucleic acid coding for or capable of encoding a proteinaceous molecule, peptide or polypeptide, and may include an RNA molecule, or a DNA molecule.

The term ‘expression’ comprises both endogenous expression and non-endogenous expression, including overexpression by transduction.

The term ‘expression inhibitory agent’ or ‘expression inhibiting agent’ means an agent, e.g. a polynucleotide designed to interfere or capable of interfering selectively with the transcription, translation and/or expression of a specific polypeptide or protein normally expressed within or by a cell. More particularly and by example, ‘expression inhibitory agent’ comprises a DNA or RNA molecule that contains a nucleotide sequence identical to or complementary to at least about 15-30, particularly at least 17, sequential nucleotides within the polyribonucleotide sequence coding for a specific polypeptide or protein. Exemplary such expression inhibitory molecules include ribozymes, microRNAs, double stranded siRNA molecules, self-complementary single-stranded siRNA molecules, genetic antisense constructs, and synthetic RNA antisense molecules with modified stabilized backbones.

The term “RNAi inhibitor” refers to any molecule that can down regulate, reduce or inhibit RNA interference function or activity in a cell or organism. An RNAi inhibitor can down regulate, reduce or inhibit RNAi (e.g., RNAi mediated cleavage of a target polynucleotide, translational inhibition, or transcriptional silencing) by interaction with or interfering with the function of any component of the RNAi pathway, including protein components such as RISC, or nucleic acid components such as miRNAs or siRNAs. A RNAi inhibitor can be an siNA molecule, an antisense molecule, an aptamer, or a small molecule that interacts with or interferes with the function of RISC, a miRNA, or an siRNA or any other component of the RNAi pathway in a cell or organism. By inhibiting RNAi (e.g. RNAi mediated cleavage of a target polynucleotide, translational inhibition, or transcriptional silencing), an RNAi inhibitor of the invention can be used to modulate (e.g., down regulate) the expression of a target gene.

The term “microRNA” or “miRNA” or “miR” as used herein refers to its meaning as is generally accepted in the art. More specifically, the term refers a small double-stranded RNA molecules that regulate the expression of target messenger RNAs either by mRNA cleavage, translational repression/inhibition or heterochromatic silencing (see for example Ambros, 2004, Nature, 431, 350-355; Barrel, 2004, Cell, 1 16, 281-297; Cullen, 2004, Virus Research, 102, 3-9; He et al, 2004, Nat. Rev. Genet., 5, 522-531; Ying el al, 2004, Gene, 342, 25-28; and Sethupathy et al, 2006, RNA, 12:192-197). As used herein, the term includes mature single stranded miRNAs, precursor miRNAs (pre-miR), and variants thereof, which may be naturally occurring. In some instances, the term “miRNA” also includes primary miRNA transcripts and duplex miRNAs.

The term ‘fragment of a polynucleotide’ relates to oligonucleotides that comprise a stretch of contiguous nucleic acid residues that exhibit substantially a similar, but not necessarily identical, activity as the complete sequence. In a particular aspect, ‘fragment’ may refer to a oligonucleotide comprising a nucleic acid sequence of at least 5 nucleic acid residues (preferably, at least 10 nucleic acid residues, at least 15 nucleic acid residues, at least 20 nucleic acid residues, at least 25 nucleic acid residues, at least 40 nucleic acid residues, at least 50 nucleic acid residues, at least 60 nucleic residues, at least 70 nucleic acid residues, at least 80 nucleic acid residues, at least 90 nucleic acid residues, at least 100 nucleic acid residues, at least 125 nucleic acid residues, at least 150 nucleic acid residues, at least 175 nucleic acid residues, at least 200 nucleic acid residues, or at least 250 nucleic acid residues) of the nucleic acid sequence of said complete sequence.

The term ‘fragment of a polypeptide’ relates to peptides, oligopeptides, polypeptides, proteins, monomers, subunits and enzymes that comprise a stretch of contiguous amino acid residues, and exhibit substantially a similar, but not necessarily identical, functional or expression activity as the complete sequence. In a particular aspect, ‘fragment’ may refer to a peptide or polypeptide comprising an amino acid sequence of at least 5 amino acid residues (preferably, at least 10 amino acid residues, at least 15 amino acid residues, at least 20 amino acid residues, at least 25 amino acid residues, at least 40 amino acid residues, at least 50 amino acid residues, at least 60 amino residues, at least 70 amino acid residues, at least 80 amino acid residues, at least 90 amino acid residues, at least 100 amino acid residues, at least 125 amino acid residues, at least 150 amino acid residues, at least 175 amino acid residues, at least 200 amino acid residues, or at least 250 amino acid residues) of the amino acid sequence of said complete sequence.

The term ‘hybridization’ means any process by which a strand of nucleic acid binds with a complementary strand through base pairing. The term ‘hybridization complex’ refers to a complex formed between two nucleic acid sequences by virtue of the formation of hydrogen bonds between complementary bases. A hybridization complex may be formed in solution (for example, COt or ROt analysis) or formed between one nucleic acid sequence present in solution and another nucleic acid sequence immobilized on a solid support (for example, paper, membranes, filters, chips, pins or glass slides, or any other appropriate substrate to which cells or their nucleic acids have been fixed). The term “stringent conditions” refers to conditions that permit hybridization between polynucleotides and the claimed polynucleotides. Stringent conditions can be defined by salt concentration, the concentration of organic solvent, for example, formamide, temperature, and other conditions well known in the art. In particular, reducing the concentration of salt, increasing the concentration of formamide, or raising the hybridization temperature can increase stringency. The term ‘standard hybridization conditions’ refers to salt and temperature conditions substantially equivalent to 5×SSC and 65° C. for both hybridization and wash. However, one skilled in the art will appreciate that such ‘standard hybridization conditions’ are dependent on particular conditions including the concentration of sodium and magnesium in the buffer, nucleotide sequence length and concentration, percent mismatch, percent formamide, and the like. Also important in the determination of “standard hybridization conditions” is whether the two sequences hybridizing are RNA-RNA, DNA-DNA or RNA-DNA. Such standard hybridization conditions are easily determined by one skilled in the art according to well known formulae, wherein hybridization is typically 10-20NC below the predicted or determined Tm with washes of higher stringency, if desired.

The term ‘inhibit’ or ‘inhibiting’, in relationship to the term ‘response’ means that a response is decreased or prevented in the presence of a compound as opposed to in the absence of the compound.

The term ‘inhibition’ refers to the reduction, down regulation of a process or the elimination of a stimulus for a process, which results in the absence or minimization of the expression or activity of a protein or polypeptide.

The term ‘induction’ refers to the inducing, up-regulation, or stimulation of a process, which results in the expression, enhanced expression, activity, or increased activity of a protein or polypeptide.

The term ‘ligand’ means an endogenous, naturally occurring molecule specific for an endogenous, naturally occurring receptor.

The term ‘pharmaceutically acceptable salts’ refers to the non-toxic, inorganic and organic acid addition salts, and base addition salts, of compounds which inhibit the expression or activity of TARGETS as disclosed herein. These salts can be prepared in situ during the final isolation and purification of compounds useful in the present invention.

The term ‘polypeptide’ relates to proteins (such as TARGETS), proteinaceous molecules, fragments of proteins, monomers or portions of polymeric proteins, peptides, oligopeptides and enzymes (such as kinases, proteases, GPCR's etc.).

The term ‘polynucleotide’ means a polynucleic acid, in single or double stranded form, and in the sense or antisense orientation, complementary polynucleic acids that hybridize to a particular polynucleic acid under stringent conditions, and polynucleotides that are homologous in at least about 60 percent of its base pairs, and more particularly 70 percent of its base pairs are in common, particularly 80 percent, most particularly 90 percent, and in a special embodiment 100 percent of its base pairs. The polynucleotides include polyribonucleic acids, polydeoxyribonucleic acids, and synthetic analogues thereof. It also includes nucleic acids with modified backbones such as peptide nucleic acid (PNA), polysiloxane, and 2′-O-(2-methoxy)ethylphosphorothioate. The polynucleotides are described by sequences that vary in length, that range from about 10 to about 5000 bases, particularly about 100 to about 4000 bases, more particularly about 250 to about 2500 bases. One polynucleotide embodiment comprises from about 10 to about 30 bases in length. A special embodiment of polynucleotide is the polyribonucleotide of from about 17 to about 22 nucleotides, more commonly described as small interfering RNAs (siRNAs—double stranded siRNA molecules or self-complementary single-stranded siRNA molecules (shRNA)). Another special embodiment are nucleic acids with modified backbones such as peptide nucleic acid (PNA), polysiloxane, and 2′-O-(2-methoxy)ethylphosphorothioate, or including non-naturally occurring nucleic acid residues, or one or more nucleic acid substituents, such as methyl-, thio-, sulphate, benzoyl-, phenyl-, amino-, propyl-, chloro-, and methanocarbanucleosides, or a reporter molecule to facilitate its detection. Polynucleotides herein are selected to be ‘substantially’ complementary to different strands of a particular target DNA sequence. This means that the polynucleotides must be sufficiently complementary to hybridize with their respective strands. Therefore, the polynucleotide sequence need not reflect the exact sequence of the target sequence. For example, a non-complementary nucleotide fragment may be attached to the 5′ end of the polynucleotide, with the remainder of the polynucleotide sequence being complementary to the strand. Alternatively, non-complementary bases or longer sequences can be interspersed into the polynucleotide, provided that the polynucleotide sequence has sufficient complementarity with the sequence of the strand to hybridize therewith under stringent conditions or to form the template for the synthesis of an extension product.

The term ‘preventing’ or ‘prevention’ refers to a reduction in risk of acquiring or developing a disease or disorder (i.e., causing at least one of the clinical symptoms of the disease not to develop) in a subject that may be exposed to a disease-causing agent, or predisposed to the disease in advance of disease onset.

The term ‘prophylaxis’ is related to and encompassed in the term ‘prevention’, and refers to a measure or procedure the purpose of which is to prevent, rather than to treat or cure a disease. Non-limiting examples of prophylactic measures may include the administration of vaccines; the administration of low molecular weight heparin to hospital patients at risk for thrombosis due, for example, to immobilization; and the administration of an anti-malarial agent such as chloroquine, in advance of a visit to a geographical region where malaria is endemic or the risk of contracting malaria is high.

The term ‘subject’ includes humans and other mammals.

The term ‘TARGET’ or ‘TARGETS’ means the protein(s) identified in accordance with the assays described herein and determined to be involved in differentiation of macrophages into M2 macrophages, otherwise referred to as an alternatively-activated macrophages. The term TARGET or TARGETS includes and contemplates alternative species forms, isoforms, and variants, such as splice variants, allelic variants, alternate in frame exons, and alternative or premature termination or start sites, including known or recognized isoforms or variants thereof such as indicated in Table 1. The NCBI accession numbers are provided to assist a skilled person to identify the transcripts and polypeptides. However, the term TARGET or TARGETS is not limited to those particular versions of the sequences and encompasses functional variants of nucleic acids and polypeptides corresponding to those sequences.

‘Therapeutically effective amount’ or ‘effective amount’ means that amount of a compound or agent that will elicit the biological or medical response in or of a subject that is being sought by or is accepted by a medical doctor or other clinician.

The term ‘treating’ or ‘treatment’ of any disease or disorder refers, in one embodiment, to ameliorating the disease or disorder (i.e., arresting the disease or reducing the manifestation, extent or severity of at least one of the clinical symptoms thereof). Accordingly, ‘treating’ refers to both therapeutic treatment and prophylactic or preventative measures. Those in need of treating include those already with the disorder as well as those in which the disorder is to be prevented. The related term ‘treatment,’ as used herein, refers to the act of treating a disorder, symptom, disease or condition. In another embodiment ‘treating’ or ‘treatment’ refers to ameliorating at least one physical parameter, which may not be discernible by the subject. In yet another embodiment, ‘treating’ or ‘treatment’ refers to modulating the disease or disorder, either physically, (e.g., stabilization of a discernible symptom), physiologically, (e.g., stabilization of a physical parameter or of a physiologically measurable parameter), or both. In a further embodiment, ‘treating’ or ‘treatment’ relates to slowing the progression of the disease.

The term “vectors” also relates to plasmids as well as to viral vectors, such as recombinant viruses, or the nucleic acid encoding the recombinant virus.

The term “vertebrate cells” means cells derived from animals having vertebral structure, including fish, avian, reptilian, amphibian, marsupial, and mammalian species. Preferred cells are derived from mammalian species, and most preferred cells are human cells. Mammalian cells include feline, canine, bovine, equine, caprine, ovine, porcine, murine, such as mice and rats, and rabbits.

As used herein the term ‘fibrotic diseases’ refers to diseases characterized by excessive or persistent scarring, particularly due to excessive or abnormal production, deposition of extracellular matrix, and are that are associated with the abnormal accumulation of cells and/or fibronectin and/or collagen and/or increased fibroblast recruitment and include but are not limited to fibrosis of individual organs or tissues such as the heart, kidney, liver, joints, lung, pleural tissue, peritoneal tissue, skin, cornea, retina, musculoskeletal and digestive tract. In particular aspects, the term fibrotic diseases refers to idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis and Peyronie's disease. More particularly, the term “fibrotic diseases” refers to idiopathic pulmonary fibrosis (IPF).

The term “M2 macrophage phenotype” or “alternatively-activated macrophages” or “M2 macrophages” is used throughout to refer to the subtype of macrophages which are activated by interleukin-4 (IL-4), IL-10, or a combination thereof, and demonstrating the ability to express particular markers e.g. CCL-18, CD206 and CD163 (Mantovani et al., 2004, Prasse 2007) many subtypes of M2 phenotype are covered by this term. They would be known to a skilled person. (e.g. described in Mantovani et al., 2004, 2012).

The term “M1 macrophage phenotype” or “classically-activated macrophages” or “M1 macrophages” is used throughout to refer to the subtype of macrophages activated by bacterial lipopolysaccharide (LPS) and interferon-γ (IFN-γ). and demonstrating characteristics which include production of large amounts of pro-inflammatory signaling and effector molecules such as TNFα.

The term “M1 macrophage phenotype” or “M0 macrophages” refers to monocyte derived naive macrophages that have not yet differentiated into either M1 or M2 macrophages, characterized by the absence of CCL18 and TNFα.

TARGETS

Applicant's invention is relevant to the treatment, prevention and alleviation of fibrotic conditions and disorders, particularly associated with increased numbers of M2 macrophages or enhanced differentiation of macrophages into M2 macrophages.

The present invention is based on extensive work by the present inventors to develop an in vitro (cell-free or cell based) assay system suitable to provide a scientifically valid substitute for the naturally occurring in vivo process of macrophage differentiation. The process of differentiation of macrophages into M2 macrophages is known to be involved in fibrosis, however it is a complex process. The present invention provides an artificial model for the natural system using distinct and quantifiable in vitro parameters which is suitable for the identification of compounds able to inhibit the differentiation of macrophages into M2 macrophages, and, thus, identify compounds that may be useful in the treatment and/or prevention of fibrosis.

The present invention provides methods for assaying for drug candidate compounds useful in treatment of fibrotic conditions, particularly useful in reducing or inhibiting the differentiation of macrophages into M2 macrophages, comprising contacting the compound with a cell expressing a TARGET, and determining the relative amount or degree of inhibition of differentiation of macrophages into M2 macrophages in the presence and/or absence of the compound. The present invention provides methods for assaying for drug candidate compounds useful in treatment of fibrotic conditions, particularly useful in reducing or inhibiting the differentiation of macrophages into M2 macrophages, comprising contacting the compound with a cell expressing a TARGET, and determining the relative amount or degree of inhibition of the expression or activity of the TARGET, whereby inhibition of expression or activity of the TARGET is associated with or results in inhibition of or reduced differentiation of macrophages into M2 macrophages in the presence and/or absence of the compound. Such methods may be used to identify target proteins that act to inhibit said differentiation; alternatively, they may be used to identify compounds that down-regulate or inhibit the expression or activity of TARGET proteins. The invention provides methods for assaying for drug candidate compounds useful in the treatment of fibrosis, comprising contacting the compound with a TARGET, under conditions wherein the expression or activity of the TARGET may be measured, and determining whether the TARGET expression or activity is altered in the presence of the compound, contacting a population of macrophage cells with said test compound and measuring a property related to differentiation of macrophages into M2 macrophages. Exemplary such methods can be designed and determined by the skilled artisan. Particular such exemplary methods are provided herein.

The present invention is based on the inventors' discovery that the TARGET polypeptides and their encoding nucleic acids, identified as a result of screens described below in the Examples, are factors involved in fibrosis and in particular in differentiation of macrophages into M2 macrophages. A reduced activity or expression of the TARGET polypeptides and/or their encoding polynucleotides is causative, correlative or associated with reduced or inhibited differentiation of macrophages into M2 macrophages. Alternatively, a reduced activity or expression of the TARGET polypeptides and/or their encoding polynucleotides is causative, correlative or associated with decrease of the markers of M2 macrophages.

In a particular embodiment of the invention, the TARGET polypeptide comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 26-50 as listed in Table 1.

TABLE 1 SEQ SEQ Target GenBank ID ID Gene Nucleic Acid Acc NO: GenBank NO: Symbol #: DNA Protein Acc # Protein NAME Class S1PR2 NM_004230.3 1 NP_004221.3 26 sphingosine-1- GPCR phosphate receptor 2 USP22 NM_015276.1 2 NP_056091.1 27 ubiquitin specific Protease peptidase 22 BPNT1 NM_006085.4 3 NP_006076.4 28 3′(2′),5′-bisphosphate Phosphatase nucleotidase 1 C1RL NM_016546.2 4 NP_057630.2 29 complement Secreted/ component 1, r Extracellular subcomponent-like DCN NM_133505.2 5 NP_598012.1 30 decorin Secreted/ NM_133507.2 6 NP_598014.1 31 Extracellular NM_133506.2 7 NP_598013.1 32 NM_133504.2 8 NP_598011.1 33 NM_001920.3 9 NP_001911.1 34 NM_133503.2 10 NP_598010.1 35 EFEMP2 NM_016938.4 11 NP_058634.4 36 EGF containing Secreted/ fibulin-like Extracellular extracellular matrix protein 2 EFNB2 NM_004093.3 12 NP_004084.1 37 ephrin-B2 Receptor GPR155 NM_001033045.3 13 NP_001028217.1 38 G protein-coupled GPCR NM_152529.6 14 NP_689742.4 39 receptor 155 NM_001267050.1 15 NP_001253979.1 40 NM_001267051.1 16 NP_001253980.1 41 KCNMB4 NM_014505.5 17 NP_055320.4 42 potassium large Ion channel conductance calcium- activated channel, subfamily M, beta member 4 LIF NM_002309.4 18 NP_002300.1 43 leukemia inhibitory Secreted/ NM_001257135.1 19 NP_001244064.1 44 factor Extracellular MS4A4A NM_148975.2 20 NP_683876.1 45 membrane-spanning 4- Receptor NM_024021.3 21 NP_076926.2 46 domains, subfamily A, NM_001243266.1 22 NP_001230195.1 47 member 4A RAF1 NM_002880.3 23 NP_002871.1 48 v-raf-1 murine Kinase leukemia viral oncogene homolog 1 SLC15A3 NM_016582.2 24 NP_057666.1 49 solute carrier family Transporter 15, member 3 ZMPSTE24 NM_005857.4 25 NP_005848.2 50 zinc metallopeptidase Protease STE24

A particular embodiment of the invention comprises the GPCR TARGETs identified as SEQ ID NO: 26 and 38-41. A particular embodiment of the invention comprises the protease TARGETs identified as SEQ ID NO: 27 and 50. A particular embodiment of the invention comprises the phosphatase TARGET identified as SEQ ID NO: 28. A particular embodiment of the invention comprises the secreted/extracellular TARGETs identified as SEQ ID NO: 29, 30-35, 36 and 43-44. A particular embodiment of the invention comprises the receptor TARGETs identified as SEQ ID NO: 37, 45-47. A particular embodiment of the invention comprises the ion channel TARGET identified as SEQ ID NO: 42. A particular embodiment of the invention comprises the kinase TARGET identified as SEQ ID NO: 48. A particular embodiment of the invention comprises the transporter TARGETs identified as SEQ ID NO: 49.

Methods of the Invention

In one aspect, the present invention relates to a method for identifying a compound useful for the treatment of fibrosis, said method comprising:

-   -   a) contacting a test compound with a polypeptide comprising an         amino acid sequence selected from the group consisting of SEQ ID         NOs: 26-50, fragments and functional derivatives thereof;     -   b) measuring a binding affinity of the test compound to said         polypeptide;     -   c) contacting the test compound with a population of macrophage         cells;     -   d) measuring a property related to differentiation of         macrophages into M2 macrophages; and     -   e) identifying a compound capable of reducing or inhibiting         macrophage differentiation into M2 macrophages and demonstrating         binding affinity to said polypeptide.

In a further aspect, the present invention relates to a method for identifying a compound that reduces or inhibits differentiation of macrophages into M2 macrophages, said method comprising:

-   -   a) contacting a test compound with a nucleic acid encoding an         amino acid selected from the group consisting of SEQ ID NOs:         26-50 or a fragment or functional derivative thereof;     -   b) identifying and/or measuring a binding affinity of the test         compound to said nucleic acid;     -   c) contacting the test compound with a population of macrophage         cells;     -   d) measuring a property related to differentiation of         macrophages into M2 macrophages; and     -   e) identifying a compound capable of reducing or inhibiting         macrophage differentiation into M2 macrophages and demonstrating         binding affinity to said polypeptide.

In one aspect, the present invention relates to a method for identifying a compound that reduces or inhibits differentiation of macrophages into M2 macrophages, said method comprising:

-   -   a) contacting a test compound with a polypeptide comprising an         amino acid sequence selected from the group consisting of SEQ ID         NOs: 26-50, fragments and functional derivatives thereof or with         a nucleic acid encoding an amino acid selected from the group         consisting of SEQ ID NOs: 26-50 or a functional derivative         thereof;     -   b) identifying and/or measuring a binding affinity of the test         compound to said polypeptide or nucleic acid;     -   c) contacting the test compound with a population of macrophage         cells;     -   d) measuring a property related to or indicating differentiation         of macrophages into M2 macrophages; and     -   e) identifying a compound capable of inhibiting or reducing         macrophage differentiation into M2 macrophages and demonstrating         binding affinity to said polypeptide or nucleic acid.

In a further aspect of the above method, the nucleic acid encoding an amino acid selected from the group consisting of SEQ ID NOs: 26-50 or a functional derivative thereof may be selected from the group consisting of SEQ ID NOs: 1-25.

The order of taking these measurements is not believed to be critical to the practice of the present invention, which may be practiced in any order. In a particular aspect the method steps (c) and (d) may be performed before performing steps (a) and (b). For example, one may first perform a screening assay of a set of compounds for which no information is known respecting the compounds' binding affinity for the polypeptide. Alternatively, one may screen a set of compounds identified as having binding affinity for a polypeptide domain, or a class of compounds identified as being an inhibitor of the polypeptide.

In another aspect, steps (a)-(d) method may also be performed simultaneously in a cell-based assay by contacting a test compound with a population of macrophages, measuring a binding affinity of the test compound to a TARGET polypeptide and a property related to differentiation of macrophages into M2 macrophages, and identifying a compound capable of inhibiting of macrophage differentiation into said M2 macrophages and which demonstrates binding affinity to said polypeptide.

The binding affinity of a compound with the polypeptide TARGET can be measured by methods known in the art, such as using surface plasmon resonance biosensors (Biacore®), by saturation binding analysis with a labeled compound (for example, Scatchard and Lindmo analysis), by differential UV spectrophotometer, fluorescence polarization assay, Fluorometric Imaging Plate Reader (FLIPR®) system, Fluorescence resonance energy transfer, and Bioluminescence resonance energy transfer. The binding affinity of compounds can also be expressed in dissociation constant (Kd) or as IC₅₀ or EC₅₀. The IC₅₀ represents the concentration of a compound that is required for 50% inhibition of binding of another ligand to the polypeptide. The EC₅₀ represents the concentration required for obtaining 50% of the maximum effect in any assay that measures TARGET function. The dissociation constant, Kd, is a measure of how well a ligand binds to the polypeptide, it is equivalent to the ligand concentration required to saturate exactly half of the binding-sites on the polypeptide. Compounds with a high affinity binding have low Kd, IC₅₀ and EC₅₀ values, for example, in the range of 100 nM to 1 pM; a moderate- to low-affinity binding relates to high Kd, IC₅₀ and EC₅₀ values, for example in the micromolar range.

In one aspect, the assay method includes contacting a TARGET polypeptide with a compound that exhibits a binding affinity in the micromolar range. In an aspect, the binding affinity exhibited is at least 10 micromolar. In an aspect, the binding affinity is at least 1 micromolar. In an aspect, the binding affinity is at least 500 nanomolar.

In a particular aspect a test compound is selected based its ability to bind to a TARGET class or from a known libraries of compounds having ability to bind to a TARGET class.

In further aspect, the present invention relates to a method for identifying a compound useful for the treatment of fibrosis, said method comprising:

-   -   a) contacting a test compound with a polypeptide comprising an         amino acid sequence selected from the group consisting of SEQ ID         NOs: 26-50, functional fragments and functional derivatives         thereof;     -   b) measuring an activity of said polypeptide;     -   c) contacting the test compound with a population of macrophage         cells;     -   d) measuring a property related to differentiation of         macrophages into alternatively-activated macrophages; and     -   e) identifying a compound capable of reducing or inhibiting         differentiation of macrophages into M2 macrophages and         inhibiting the activity of said polypeptide.

In an additional aspect, the present invention relates to a method for identifying a compound that reduces or inhibits differentiation of macrophages into M2 macrophages, said method comprising:

-   -   a) contacting a test compound with a polypeptide comprising an         amino acid sequence selected from the group consisting of SEQ ID         NOs: 26-50, functional fragments and functional derivatives         thereof;     -   b) measuring an activity of said polypeptide;     -   c) contacting the test compound with a population of macrophage         cells;     -   d) measuring a property related to differentiation of         macrophages into alternatively-activated macrophages; and     -   e) identifying a compound capable of reducing or inhibiting         differentiation of macrophages into M2 macrophages and         inhibiting the activity of said polypeptide.

In a further aspect, the present invention relates to a method for identifying a compound that reduces or inhibits differentiation of macrophages into M2 macrophages, said method comprising:

-   -   a) contacting a test compound with a polypeptide comprising an         amino acid sequence selected from the group consisting of SEQ ID         NOs: 26-50, functional fragments and functional derivatives         thereof or with a nucleic acid encoding an amino acid selected         from the group consisting of SEQ ID NOs: 26-50 or a functional         derivative thereof;     -   b) measuring the expression or an activity of said polypeptide;     -   c) identifying a compound capable of inhibiting the expression         or activity of said polypeptide whereby inhibition of expression         or activity of said polypeptide results in or is associated with         reduction or inhibition of differentiation of macrophages into         M2 macrophages.

In an additional aspect of the above method, the nucleic acid encoding an amino acid selected from the group consisting of SEQ ID NOs: 26-50 or a functional derivative thereof may be selected from the group consisting of SEQ ID NOs: 1-25.

The order of taking these measurements is not believed to be critical to the practice of the present invention, which may be practiced in any order. In a particular aspect of the method steps (c) and (d) may be performed before performing steps (a) and (b). For example, one may first perform a screening assay of a set of compounds for which no information is known respecting the compounds' binding affinity for the polypeptide. Alternatively, one may screen a set of compounds identified as having binding affinity for a polypeptide domain, or a class of compounds identified as being an inhibitor of the polypeptide.

Table 1 lists the TARGETS identified using applicants' knock-down library in the M2 differentiation assay exemplified herein, including the class of polypeptides identified. TARGETS have been identified in polypeptide classes including kinases, proteases, enzymes, ion channels, GPCRs, and extracellular proteins, for instance. A skilled artisan would be aware of different methods of measuring activity of those classes both in cell-free preparations as well in cell-based assays. A variety of methods exists and might be adapted to a particular target. Those adaptations are a matter of routine experimentation and rely on the existent techniques and methods. Some exemplary methods are described herein.

Ion channels are membrane protein complexes and their function is to facilitate the diffusion of ions across biological membranes. Membranes, or phospholipid bilayers, build a hydrophobic, low dielectric barrier to hydrophilic and charged molecules. Ion channels provide a high conducting, hydrophilic pathway across the hydrophobic interior of the membrane. The activity of an ion channel can be measured using classical patch clamping. High-throughput fluorescence-based or tracer-based assays are also widely available to measure ion channel activity. These fluorescent-based assays screen compounds on the basis of their ability to either open or close an ion channel thereby changing the concentration of specific fluorescent dyes across a membrane. In the case of the tracer-based assay, the changes in concentration of the tracer within and outside the cell are measured by radioactivity measurement or gas absorption spectrometry.

Specific methods to determine the inhibition by the compound by measuring the cleavage of the substrate by the polypeptide, which is a protease, are well known in the art. Classically, substrates are used in which a fluorescent group is linked to a quencher through a peptide sequence that is a substrate that can be cleaved by the target protease. Cleavage of the linker separates the fluorescent group and quencher, giving rise to an increase in fluorescence.

G-protein coupled receptors (GPCR) are capable of activating an effector protein, resulting in changes in second messenger levels in the cell. The TARGETs represented by SEQ ID NO: 26, 38-41 are GPCRs. The activity of a GPCR can be measured by measuring the activity level of such second messengers. Two important and useful second messengers in the cell are cyclic AMP (cAMP) and Ca²⁺. The activity levels can be measured by methods known to persons skilled in the art, either directly by ELISA or radioactive technologies or by using substrates that generate a fluorescent or luminescent signal when contacted with Ca²⁺ or indirectly by reporter gene analysis. The activity level of the one or more secondary messengers may typically be determined with a reporter gene controlled by a promoter, wherein the promoter is responsive to the second messenger. Promoters known and used in the art for such purposes are the cyclic-AMP responsive promoter that is responsive for the cyclic-AMP levels in the cell, and the NF-AT responsive promoter that is sensitive to cytoplasmic Ca²⁺-levels in the cell. The reporter gene typically has a gene product that is easily detectable. The reporter gene can either be stably infected or transiently transfected in the host cell. Useful reporter genes are alkaline phosphatase, enhanced green fluorescent protein, destabilized green fluorescent protein, luciferase and β-galactosidase.

In another aspect the present relation relates to a method for identifying a compound useful for the treatment of fibrosis, said method comprising

-   -   a) contacting a test compound with population of macrophage         cells expressing a polypeptide comprising an amino acid sequence         selected from the group consisting of SEQ ID NOs: 26-50;     -   b) measuring expression, activity and/or amount of said         polypeptide in said cells;     -   c) measuring a property related to differentiation of         macrophages into M2 macrophages; and     -   d) identifying a compound producing reduction of expression,         activity and/or amount of said polypeptide and capable of         reducing or inhibiting differentiation of macrophages into M2         macrophages.

In a further aspect the present relation relates to a method for identifying a compound that reduces or inhibits differentiation of macrophages into M2 macrophages, said method comprising

-   -   a) contacting a test compound with population of macrophage         cells expressing a polypeptide comprising an amino acid sequence         selected from the group consisting of SEQ ID NOs: 26-50;     -   b) measuring expression, activity and/or amount of said         polypeptide in said cells;     -   c) optionally measuring a property related to differentiation of         macrophages into M2 macrophages; and     -   d) identifying a compound producing reduction of expression,         activity and/or amount of said polypeptide and capable of         reducing or inhibiting differentiation of macrophages into M2         macrophages.

In particular aspect the method steps of the invention related to measuring of binding to a TARGET or activity are performed with a population of mammalian cells, in particular human cells, which have been engineered so as to express said TARGET polypeptide. In an alternative aspect the methods of the invention are performed using a population of macrophages, which have been engineered so as to express said TARGET polypeptide. This can be achieved by expression of the TARGET polypeptide in the cells using appropriate techniques known to a skilled person. In a specific embodiment, this can be achieved by over-expression of the TARGET polypeptide in the cells using appropriate techniques known to a skilled person. Alternatively, the method of the invention may be performed with a population of macrophages which are known to naturally express said TARGET polypeptide.

In particular aspect the measurements of expression and/or amount of a TARGET polypeptide and a measurement of a property related to differentiation of macrophages into M2 macrophages can be done in separate steps using different populations of macrophage cells. The measurements in steps (b) and (c) can also be performed in reverse order. The order of taking these measurements is not believed to be critical to the practice of the present invention, which may be practiced in any order.

One particular means of measuring the activity or expression of the polypeptide is to determine the amount of said polypeptide using a polypeptide binding agent, such as an antibody, or to determine the activity of said polypeptide in a biological or biochemical measure, for instance the amount of phosphorylation of a target of a kinase polypeptide.

TARGET gene expression (mRNA levels) can be measured using techniques well-known to a skilled artisan. Particular examples of such techniques include northern analysis or real-time PCR. Those methods are indicative of the presence of nucleic acids encoding TARGETs in a sample, and thereby correlate with the expression of the transcript from the polynucleotide.

The population of cells may be exposed to the compound or the mixture of compounds through different means, for instance by direct incubation in the medium, or by nucleic acid transfer into the cells. Such transfer may be achieved by a wide variety of means, for instance by direct transfection of naked isolated DNA, or RNA, or by means of delivery systems, such as recombinant vectors. Other delivery means such as liposomes, or other lipid-based vectors may also be used. Particularly, the nucleic acid compound is delivered by means of a (recombinant) vector such as a recombinant virus.

In vivo animal models of fibrotic diseases may be utilized by the skilled artisan to further or additionally screen, assess, and/or verify the agents or compounds identified in the present invention, including further assessing TARGET modulation in vivo. Such animal models include, but are not limited to, lung fibrosis models (e.g Bleomycin model, irradiation model, silica model, (inducible) transgenic mouse model, FITC model, adoptive transfer model), renal fibrosis models (e.g. COL4A3-deficiency model, nephrotoxic serum nephritis model; unilateral ureteral obstruction model) and liver fibrosis models (e.g CCL4 intoxication model).

A population of macrophage cells in the methods of the invention does not have to be pure or require a particular degree of purity. A population of mammalian cells wherein some of said cells are macrophage cells is sufficient to practice the methods of present invention. The number or amount of macrophage cells should be sufficient to determine whether there are significant or relevant changes in differentiation into M2 macrophages or in relative amounts of M2 macrophages, including versus other types such as M1 macrophages, or should be sufficient to evaluate differences, such as a significant decrease or increase, in a macrophage marker or factor. In particular aspect said marker is CCL18. In one aspect such population of macrophage cells can be derived from another cell type (e.g. monocytes) or any other cells that can potentially differentiate into macrophage cells. It should be understood that a population of macrophage cells can be also obtained directly from an organ or alternatively grown using appropriate medium. The techniques of generating a population of macrophage cells are known to a person skilled in the art. Some of such techniques are provided in the Examples of the invention.

In a specific embodiment the methods may additionally comprise the step of comparing the compound to be tested to a control. Suitable controls should always be in place to insure against false positive or negative readings. In a particular embodiment of the present invention the screening method comprises the additional step of comparing the compound to a suitable control. In one embodiment, the control may be a cell or a sample that has not been in contact with the test compound. In an alternative embodiment, the control may be a cell that does not express the TARGET; for example in one aspect of such an embodiment the test cell may naturally express the TARGET and the control cell may have been contacted with an agent, e.g. an siRNA, which inhibits or prevents expression of the TARGET. Alternatively, in another aspect of such an embodiment, the cell in its native state does not express the TARGET and the test cell has been engineered so as to express the TARGET, so that in this embodiment, the control could be the untransformed native cell. The control may also alternatively utilize a known inhibitor of differentiation of macrophages into M2 macrophages or a compound known not to have any significant effect on the M2 macrophages. Whilst exemplary controls are described herein, this should not be taken as limiting; it is within the scope of a person of skill in the art to select appropriate controls for the experimental conditions being used.

Examples of negative controls include, but not limited to, cells that have been not treated with any compound, cells treated with a compound known not to be an inhibitor of differentiation of macrophages into M2 macrophages, compounds known not to interfere with the pathways involved in differentiation of macrophages into M2 macrophages. Examples of positive controls include, but not limited to, cells contacted with compounds known to inhibit activity or expression of STAT6, IL4R, JAK1 or CCL18, cells contacted with a compound known to inhibit the differentiation of macrophages into M2 macrophages.

In a particular embodiment the binding and activity testing in the invention methods is performed in an in vitro cell-free preparation.

In an alternative embodiment the binding and activity testing in the invention methods is performed in a cell.

In a particular aspect the invention methods activity and binding testing is performed in a mammalian cell, particularly a human cell. More specifically these steps are performed in macrophage cells.

It should be understood that the cells expressing the polypeptides may be cells naturally expressing the polypeptides, or the cells may be may be transfected to express the polypeptides. Also, the cells may be transduced to overexpress the polypeptide, or may be transfected to express a non-endogenous form of the polypeptide, which can be differentially assayed or assessed.

The polynucleotide expressing the TARGET polypeptide in cells might be included within a vector. The polynucleic acid is operably linked to signals enabling expression of the nucleic acid sequence and is introduced into a cell utilizing, particularly, recombinant vector constructs, which will express the nucleic acid once the vector is introduced into the cell. A variety of viral-based systems are available, including adenoviral, retroviral, adeno-associated viral, lentiviral, herpes simplex viral or a sendai viral vector systems. All may be used to introduce and express a TARGET polypeptide in the target cells.

In a particular embodiment the assay methods of the invention involve measurement of the inhibition of release or expression of a marker of alternatively-activated macrophages (M2 macrophage marker).

Many of the M2 macrophage markers are known to a skilled person. The selection of such markers depends on the availability of reagents, scale of the practiced assay methods and other factors related to a specific assay design. In a specific embodiment a M2 macrophage marker is selected from the group consisting of CCL18, CCL13, TGFβ, CCL22, CCL17, soluble fibronectin, folate receptor β, CD206, and CD163. In a specific embodiment the M2 macrophage marker is CCL18 or CD206.

The means of measuring such markers, depending on the assay setup and throughput, are known to a skilled artisan. Although human ELISA's are commercially available their sensitivity is not always to detect low levels of the markers. Therefore, the assay might be optimized on the Meso Scale Discovery platform (MSD) (Meso Scale Discovery, Maryland, US) as a sandwich immunoassay where signaling molecules are specifically captured and detected by antibodies. MSD technology uses micro-plates with carbon electrodes integrated at the bottom of the plates; Biological reagents, immobilized to the carbon simply by passive adsorption, retain high biological activity. MSD assays use electro-chemiluminescent labels for ultra-sensitive detection. The detection process is initiated at electrodes located at the bottom of the micro-plates. Labels near the electrode only are excited and detected reducing background signal. The antibodies for such assay might be purchased from different producers and the skilled artisan is in the position to choose correct antibodies to perform the assay.

Alternatively the expression levels of the M1 and M2 phenotype markers can be measured using known methods including quantitative real time polymerase chain reaction (Q-PCR/qPCR/qrt-PCR). qPCR is a laboratory technique based on PCR, which is used to amplify and simultaneously quantify a targeted DNA molecule. For one or more specific sequences in a DNA sample, Real Time-PCR enables both detection and quantification. The quantity can be either an absolute number of copies or a relative amount when normalized to DNA input or additional normalizing genes.

In a specific embodiment the methods of the invention utilize cells that have been triggered by a factor which induces macrophage differentiation into M2 macrophages (M2 inducing factor). Many of such factors have been described in the literature and they are well-known to a skilled person. In a particular embodiment the methods of the invention utilize cells that have been triggered by one or more M2 inducing factors selected from the group consisting of IL4, IL10, IL13, immune complexes, and lipopolysaccharides. An immune complex is formed from the integral binding of an antibody to a soluble antigen. The bound antigen and antibody act as a specific epitope, and is referred to as a singular immune complex.

In more particular embodiment the assay methods are performed using cells that have been triggered by a combination of IL10 and IL4.

In a particular embodiment the assay methods might be supplemented by additional steps of: measuring a property related to the differentiation of macrophages into classically-activated (M1) macrophages, and identifying a compound that does not inhibit said differentiation. In a specific embodiment said property is the level and/or expression of a marker of the M1 macrophage phenotype (M1 macrophage marker), and a compound is identified which does not increase the levels of said marker.

In a particular embodiment TNFα is used as a marker of the M1 macrophage phenotype. Many other alternative M1 macrophage markers have been described in the literature and will be known to a skilled person.

Candidate Compounds Expression-Inhibiting Agents

In a particular embodiment the methods of the invention a test compound is selected from the group consisting of an antisense polynucleotide, a ribozyme, short-hairpin RNA (shRNA), microRNA (miRNA) and a small interfering RNA (siRNA).

A special embodiment of these methods comprises the expression-inhibitory agent selected from the group consisting of antisense RNA, antisense oligodeoxynucleotide (ODN), a ribozyme that cleaves the polyribonucleotide coding for SEQ ID NO: 26-50, a small interfering RNA (siRNA) or microRNA (miRNA) that is sufficiently homologous to a portion of the polyribonucleotide corresponding to SEQ ID NO: 1-25, such that the expression-inhibitory agent interferes with the translation of the TARGET polyribonucleotide to the TARGET polypeptide.

The down regulation of gene expression using antisense nucleic acids can be achieved at the translational or transcriptional level. Antisense nucleic acids of the invention are particularly nucleic acid fragments capable of specifically hybridizing with all or part of a nucleic acid encoding a TARGET polypeptide or the corresponding messenger RNA. In addition, antisense nucleic acids may be designed which decrease expression of the nucleic acid sequence capable of encoding a TARGET polypeptide by inhibiting splicing of its primary transcript. Any length of antisense sequence is suitable for practice of the invention so long as it is capable of down-regulating or blocking expression of a nucleic acid coding for a TARGET. Particularly, the antisense sequence is at least about 15-30, and particularly at least 17 nucleotides in length. The preparation and use of antisense nucleic acids, DNA encoding antisense RNAs and the use of oligo and genetic antisense is known in the art.

In a more specific embodiment a test compound comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a TARGET polynucleotide.

The skilled artisan can readily utilize any of several strategies to facilitate and simplify the selection process for antisense nucleic acids and oligonucleotides effective in inhibition of TARGET and differentiation of macrophages into alternatively-activated macrophages. Predictions of the binding energy or calculation of thermodynamic indices between an oligonucleotide and a complementary sequence in an mRNA molecule may be utilized (Chiang et al. (1991) J. Biol. Chem. 266:18162-18171; Stull et al. (1992) Nucl. Acids Res. 20:3501-3508). Antisense oligonucleotides may be selected on the basis of secondary structure (Wickstrom et al (1991) in Prospects for Antisense Nucleic Acid Therapy of Cancer and AIDS, Wickstrom, ed., Wiley-Liss, Inc., New York, pp. 7-24; Lima et al. (1992) Biochem. 31:12055-12061). Schmidt and Thompson (U.S. Pat. No. 6,416,951) describe a method for identifying a functional antisense agent comprising hybridizing an RNA with an oligonucleotide and measuring in real time the kinetics of hybridization by hybridizing in the presence of an intercalation dye or incorporating a label and measuring the spectroscopic properties of the dye or the label's signal in the presence of unlabelled oligonucleotide. In addition, any of a variety of computer programs may be utilized which predict suitable antisense oligonucleotide sequences or antisense targets utilizing various criteria recognized by the skilled artisan, including for example the absence of self-complementarity, the absence of hairpin loops, the absence of stable homodimer and duplex formation (stability being assessed by predicted energy in kcal/mol). Examples of such computer programs are readily available and known to the skilled artisan and include the OLIGO 4 or OLIGO 6 program (Molecular Biology Insights, Inc., Cascade, Colo.) and the Oligo Tech program (Oligo Therapeutics Inc., Wilsonville, Oreg.). In addition, antisense oligonucleotides suitable in the present invention may be identified by screening an oligonucleotide library, or a library of nucleic acid molecules, under hybridization conditions and selecting for those which hybridize to the target RNA or nucleic acid (see for example U.S. Pat. No. 6,500,615). Mishra and Toulme have also developed a selection procedure based on selective amplification of oligonucleotides that bind target (Mishra et al (1994) Life Sciences 317:977-982). Oligonucleotides may also be selected by their ability to mediate cleavage of target RNA by RNAse H, by selection and characterization of the cleavage fragments (Ho et al (1996) Nucl Acids Res 24:1901-1907; Ho et al (1998) Nature Biotechnology 16:59-630). Generation and targeting of oligonucleotides to GGGA motifs of RNA molecules has also been described (U.S. Pat. No. 6,277,981).

The antisense nucleic acids are particularly oligonucleotides and may consist entirely of deoxyribo-nucleotides, modified deoxyribonucleotides, or some combination of both. The antisense nucleic acids can be synthetic oligonucleotides. The oligonucleotides may be chemically modified, if desired, to improve stability and/or selectivity. Specific examples of some particular oligonucleotides envisioned for this invention include those containing modified backbones, for example, phosphorothioates, phosphotriesters, methyl phosphonates, short chain alkyl or cycloalkyl intersugar linkages or short chain heteroatomic or heterocyclic intersugar linkages. Since oligonucleotides are susceptible to degradation by intracellular nucleases, the modifications can include, for example, the use of a sulfur group to replace the free oxygen of the phosphodiester bond. This modification is called a phosphorothioate linkage. Phosphorothioate antisense oligonucleotides are water soluble, polyanionic, and resistant to endogenous nucleases. In addition, when a phosphorothioate antisense oligonucleotide hybridizes to its TARGET site, the RNA-DNA duplex activates the endogenous enzyme ribonuclease (RNase) H, which cleaves the mRNA component of the hybrid molecule. Oligonucleotides may also contain one or more substituted sugar moieties. Particular oligonucleotides comprise one of the following at the 2′ position: OH, SH, SCH3, F, OCN, heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; an RNA cleaving group; a reporter group; an intercalator; a group for improving the pharmacokinetic properties of an oligonucleotide; or a group for improving the pharmacodynamic properties of an oligonucleotide and other substituents having similar properties. Similar modifications may also be made at other positions on the oligonucleotide, particularly the 3′ position of the sugar on the 3′ terminal nucleotide and the 5′ position of 5′ terminal nucleotide.

In addition, antisense oligonucleotides with phosphoramidite and polyamide (peptide) linkages can be synthesized. These molecules should be very resistant to nuclease degradation. Furthermore, chemical groups can be added to the 2′ carbon of the sugar moiety and the 5 carbon (C-5) of pyrimidines to enhance stability and facilitate the binding of the antisense oligonucleotide to its TARGET site. Modifications may include 2′-deoxy, 0-pentoxy, 0-propoxy, 0-methoxy, fluoro, methoxyethoxy phosphorothioates, modified bases, as well as other modifications known to those of skill in the art.

Another type of expression-inhibitory agent that reduces the levels of TARGETS is the ribozyme. Ribozymes are catalytic RNA molecules (RNA enzymes) that have separate catalytic and substrate binding domains. The substrate binding sequence combines by nucleotide complementarity and, possibly, non-hydrogen bond interactions with its TARGET sequence. The catalytic portion cleaves the TARGET RNA at a specific site. The substrate domain of a ribozyme can be engineered to direct it to a specified mRNA sequence. The ribozyme recognizes and then binds a TARGET mRNA through complementary base pairing. Once it is bound to the correct TARGET site, the ribozyme acts enzymatically to cut the TARGET mRNA. Cleavage of the mRNA by a ribozyme destroys its ability to direct synthesis of the corresponding polypeptide. Once the ribozyme has cleaved its TARGET sequence, it is released and can repeatedly bind and cleave at other mRNAs.

Exemplary ribozyme forms include a hammerhead motif, a hairpin motif, a hepatitis delta virus, group I intron or RNaseP RNA (in association with an RNA guide sequence) motif or Neurospora VS RNA motif Ribozymes possessing a hammerhead or hairpin structure are readily prepared since these catalytic RNA molecules can be expressed within cells from eukaryotic promoters (Chen, et al. (1992) Nucleic Acids Res. 20:4581-9). A ribozyme of the present invention can be expressed in eukaryotic cells from the appropriate DNA vector. If desired, the activity of the ribozyme may be augmented by its release from the primary transcript by a second ribozyme (Ventura, et al. (1993) Nucleic Acids Res. 21:3249-55).

Ribozymes may be chemically synthesized by combining an oligodeoxyribonucleotide with a ribozyme catalytic domain (20 nucleotides) flanked by sequences that hybridize to the TARGET mRNA after transcription. The oligodeoxyribonucleotide is amplified by using the substrate binding sequences as primers. The amplification product is cloned into a eukaryotic expression vector.

Ribozymes are expressed from transcription units inserted into DNA, RNA, or viral vectors. Transcription of the ribozyme sequences are driven from a promoter for eukaryotic RNA polymerase I (pol (I), RNA polymerase II (pol II), or RNA polymerase III (pol III). Transcripts from pol II or pol III promoters will be expressed at high levels in all cells; the levels of a given pol II promoter in a given cell type will depend on nearby gene regulatory sequences. Prokaryotic RNA polymerase promoters are also used, providing that the prokaryotic RNA polymerase enzyme is expressed in the appropriate cells (Gao and Huang, (1993) Nucleic Acids Res. 21:2867-72). It has been demonstrated that ribozymes expressed from these promoters can function in mammalian cells (Kashani-Sabet, et al. (1992) Antisense Res. Dev. 2:3-15).

In a particular embodiment the methods of the invention might be practiced using antisense polynucleotide, siRNA or shRNA comprising an antisense strand of 17-25 nucleotides complementary to a sense strand, wherein said sense strand is selected from 17-25 continuous nucleotides of a TARGET polynucleotide.

A particular inhibitory agent is a small interfering RNA (siRNA, particularly small hairpin RNA, “shRNA”). siRNA, particularly shRNA, mediate the post-transcriptional process of gene silencing by double stranded RNA (dsRNA) that is homologous in sequence to the silenced RNA. siRNA according to the present invention comprises a sense strand of 15-30, particularly 17-30, most particularly 17-25 nucleotides complementary or homologous to a contiguous 17-25 nucleotide sequence selected from the group of sequences described in SEQ ID NO: 1-25, more particularly from the group of sequences described in SEQ ID NOs: 64-109, and an antisense strand of 15-30, particularly 17-30, most particularly 17-25, more specifically 19-21 nucleotides complementary to the sense strand. More particular siRNA according to the present invention comprises a sense strand selected from the group of sequences comprising SEQ ID NOs: 64-109. The most particular siRNA comprises sense and anti-sense strands that are 100 percent complementary to each other and the TARGET polynucleotide sequence. Particularly the siRNA further comprises a loop region linking the sense and the antisense strand.

A self-complementing single stranded shRNA molecule polynucleotide according to the present invention comprises a sense portion and an antisense portion connected by a loop region linker. Particularly, the loop region sequence is 4-30 nucleotides long, more particularly 5-15 nucleotides long and most particularly 8 or 12 nucleotides long. In a most particular embodiment the linker sequence is UUGCUAUA or GUUUGCUAUAAC (SEQ ID NO: 110). Self-complementary single stranded siRNAs form hairpin loops and are more stable than ordinary dsRNA. In addition, they are more easily produced from vectors.

Analogous to antisense RNA, the siRNA can be modified to confirm resistance to nucleolytic degradation, or to enhance activity, or to enhance cellular distribution, or to enhance cellular uptake, such modifications may consist of modified internucleoside linkages, modified nucleic acid bases, modified sugars and/or chemical linkage the siRNA to one or more moieties or conjugates. The nucleotide sequences are selected according to siRNA designing rules that give an improved reduction of the TARGET sequences compared to nucleotide sequences that do not comply with these siRNA designing rules (For a discussion of these rules and examples of the preparation of siRNA, WO 2004/094636 and US 2003/0198627, are hereby incorporated by reference).

Particular inhibitory agents include MicroRNAs (referred to as “miRNAs”). miRNA are small non-coding RNAs, belonging to a class of regulatory molecules found in many eukaryotic species that control gene expression by binding to complementary sites on target messenger RNA (mRNA) transcripts.

In vivo miRNAs are generated from larger RNA precursors (termed pre-miRNAs) that are processed in the nucleus into approximately 70 nucleotide pre-miRNAs, which fold into imperfect stem-loop structures. The pre-miRNAs undergo an additional processing step within the cytoplasm where mature miRNAs of 18-25 nucleotides in length are excised from one side of the pre-miRNA hairpin by an RNase III enzyme.

miRNAs have been shown to regulate gene expression in two ways. First, miRNAs binding to protein-coding mRNA sequences that are exactly complementary to the miRNA induce the RNA-mediated interference (RNAi) pathway. Messenger RNA targets are cleaved by ribonucleases in the RISC complex. In the second mechanism, miRNAs that bind to imperfect complementary sites on messenger RNA transcripts direct gene regulation at the posttranscriptional level but do not cleave their mRNA targets. miRNAs identified in both plants and animals use this mechanism to exert translational control over their gene targets.

Low Molecular Weight Compounds

Particular drug candidate compounds are low molecular weight compounds. Low molecular weight compounds, for example with a molecular weight of 500 Dalton or less, are likely to have good absorption and permeation in biological systems and are consequently more likely to be successful drug candidates than compounds with a molecular weight above 500 Dalton (Lipinski et al., 2001)). Peptides comprise another particular class of drug candidate compounds. Peptides may be excellent drug candidates and there are multiple examples of commercially valuable peptides such as fertility hormones and platelet aggregation inhibitors. Natural compounds are another particular class of drug candidate compound. Such compounds are found in and extracted from natural sources, and which may thereafter be synthesized. The lipids are another particular class of drug candidate compound.

Antibodies

Another preferred class of drug candidate compounds is an antibody. The present invention also provides antibodies directed against the TARGETS. These antibodies may be endogenously produced to bind to the TARGETS within the cell, or added to the tissue to bind to the TARGET polypeptide present outside the cell. These antibodies may be monoclonal antibodies or polyclonal antibodies. The present invention includes chimeric, single chain, and humanized antibodies, as well as FAb fragments and the products of a FAb expression library, and Fv fragments and the products of an Fv expression library.

In certain embodiments, polyclonal antibodies may be used in the practice of the invention. The skilled artisan knows methods of preparing polyclonal antibodies. Polyclonal antibodies can be raised in a mammal, for example, by one or more injections of an immunizing agent and, if desired, an adjuvant. Typically, the immunizing agent and/or adjuvant will be injected in the mammal by multiple subcutaneous or intraperitoneal injections. Antibodies may also be generated against the intact TARGET protein or polypeptide, or against a fragment, derivatives including conjugates, or other epitope of the TARGET protein or polypeptide, such as the TARGET embedded in a cellular membrane, or a library of antibody variable regions, such as a phage display library.

It may be useful to conjugate the immunizing agent to a protein known to be immunogenic in the mammal being immunized Examples of such immunogenic proteins include but are not limited to keyhole limpet hemocyanin, serum albumin, bovine thyroglobulin, and soybean trypsin inhibitor. Examples of adjuvants that may be employed include Freund's complete adjuvant and MPL-TDM adjuvant (monophosphoryl Lipid A, synthetic trehalose dicorynomycolate). One skilled in the art without undue experimentation may select the immunization protocol.

In some embodiments, the antibodies may be monoclonal antibodies. Monoclonal antibodies may be prepared using methods known in the art. The monoclonal antibodies of the present invention may be “humanized” to prevent the host from mounting an immune response to the antibodies. A “humanized antibody” is one in which the complementarity determining regions (CDRs) and/or other portions of the light and/or heavy variable domain framework are derived from a non-human immunoglobulin, but the remaining portions of the molecule are derived from one or more human immunoglobulins. Humanized antibodies also include antibodies characterized by a humanized heavy chain associated with a donor or acceptor unmodified light chain or a chimeric light chain, or vice versa. The humanization of antibodies may be accomplished by methods known in the art (see, e.g. Mark and Padlan, (1994) “Chapter 4. Humanization of Monoclonal Antibodies”, The Handbook of Experimental Pharmacology Vol. 113, Springer-Verlag, New York). Transgenic animals may be used to express humanized antibodies.

Human antibodies can also be produced using various techniques known in the art, including phage display libraries (Hoogenboom and Winter, (1991) J. Mol. Biol. 227:381-8; Marks et al. (1991). J. Mol. Biol. 222:581-97). The techniques of Cole, et al. and Boerner, et al. are also available for the preparation of human monoclonal antibodies (Cole, et al. (1985) Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p. 77; Boerner, et al (1991). J. Immunol., 147(1):86-95).

Techniques known in the art for the production of single chain antibodies can be adapted to produce single chain antibodies to the TARGETS. The antibodies may be monovalent antibodies. Methods for preparing monovalent antibodies are well known in the art. For example, one method involves recombinant expression of immunoglobulin light chain and modified heavy chain. The heavy chain is truncated generally at any point in the Fc region so as to prevent heavy chain cross-linking. Alternatively; the relevant cysteine residues are substituted with another amino acid residue or are deleted so as to prevent cross-linking.

Bispecific antibodies are monoclonal, preferably human or humanized, antibodies that have binding specificities for at least two different antigens and preferably for a cell-surface protein or receptor or receptor subunit. In the present case, one of the binding specificities is for one domain of the TARGET; the other one is for another domain of the TARGET.

Methods for making bispecific antibodies are known in the art. Traditionally, the recombinant production of bispecific antibodies is based on the co-expression of two immunoglobulin heavy-chain/light-chain pairs, where the two heavy chains have different specificities (Milstein and Cuello, (1983) Nature 305:537-9). Because of the random assortment of immunoglobulin heavy and light chains, these hybridomas (quadromas) produce a potential mixture of ten different antibody molecules, of which only one has the correct bispecific structure. Affinity chromatography steps usually accomplish the purification of the correct molecule. Similar procedures are disclosed in Trauneeker, et al. (1991) EMBO J. 10:3655-9.

A special aspect of the methods of the present invention relates to the down-regulation or blocking of the expression of a TARGET polypeptide by the induced expression of a polynucleotide encoding an intracellular binding protein that is capable of selectively interacting with the TARGET polypeptide. An intracellular binding protein includes an activity-inhibitory agent and any protein capable of selectively interacting, or binding, with the polypeptide in the cell in which it is expressed and neutralizing the function of the polypeptide. Particularly, the intracellular binding protein may be an antibody, particularly a neutralizing antibody, or a fragment of an antibody or neutralizing antibody having binding affinity to an epitope of the TARGET polypeptide of SEQ ID NO: 26-50. More particularly, the intracellular binding protein is a single chain antibody.

Pharmaceutical Compositions, Related Uses and Methods

The antibodies or a fragments thereof which specifically bind to a TARGET polypeptide and expression inhibiting agents selected from the group consisting of an antisense polynucleotide, a ribozyme, a small interfering RNA (siRNA), microRNA (miRNA) and a short-hairpin RNA (shRNA) that may be used as therapeutic agents for the treatment of conditions in mammals that are causally related or attributable to differentiation of macrophages into M2 macrophages.

The present invention relates to pharmaceutical compositions comprising an antibody or a fragment thereof which specifically binds to a TARGET polypeptide, for use in the treatment of a fibrotic condition. In a particular embodiment a fibrotic condition is fibrotic diseases associated with differentiation of macrophages into M2 macrophages.

In particular aspect, the present invention provides a method of treating a mammal having, or at risk of having a fibrotic disease, said method comprising administering an effective condition-treating or condition-preventing amount of one or more of the pharmaceutical compositions comprising an antibody or a fragment thereof which specifically binds to a TARGET polypeptide. In a particular aspect, the present invention provides a method of treating a mammal having, or at risk of having idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In specific embodiment, said antibody is a monoclonal antibody. In alternative embodiment said antibody is a single chain antibody. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

In another aspect the present invention provides an antibody or a fragment thereof which specifically binds to a TARGET polypeptide for use in the treatment, and/or prophylaxis of a fibrotic condition. In a specific embodiment, said fibrotic condition is selected from idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In specific embodiment, said antibody is a monoclonal antibody. In alternative embodiment said antibody is a single chain antibody. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

In yet another aspect, the present invention provides an antibody or a fragment thereof which specifically binds to a TARGET polypeptide, or a pharmaceutical composition comprising an antibody or a fragment thereof which specifically binds to a TARGET polypeptide for use in the manufacture of a medicament for the treatment, or prophylaxis of a fibrotic condition. In a specific embodiment, said fibrotic condition is selected from idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In specific embodiment, said antibody is a monoclonal antibody. In alternative embodiment said antibody is a single chain antibody. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

A particular regimen of the present method comprises the administration to a subject suffering from a fibrotic disease involving differentiation of macrophages into M2 macrophages, of an effective amount of an antibody or a fragment thereof which specifically binds to a TARGET polypeptide for a period of time sufficient to reduce the level of abnormal fibrosis in the subject, and preferably terminate the processes responsible for said fibrotic condition. A special embodiment of the method comprises administering of an effective amount of an antibody or a fragment thereof which specifically binds to a TARGET polypeptide to a subject patient suffering from or susceptible to the development of a fibrotic disease, for a period of time sufficient to reduce or prevent, respectively, fibrotic condition in said patient, and preferably terminate, the processes responsible for said fibrotic condition. In specific embodiment, said antibody is a monoclonal antibody. In alternative embodiment said antibody is a single chain antibody. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

The present invention further relates to compositions comprising said agents, wherein said agent is selected from the group consisting of an antisense polynucleotide, a ribozyme, a small interfering RNA (siRNA), microRNA (miRNA), and a short-hairpin RNA (shRNA), wherein said agent comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1-25. These agents are, otherwise, referred herein to as expression inhibitory agents.

In particular aspect, the present invention provides a method of treating a mammal having, or at risk of having a fibrotic disease, said method comprising administering an effective condition-treating or condition-preventing amount of one or more of the pharmaceutical compositions comprising said expression inhibitory agent. In a particular aspect, the present invention provides a method of treating a mammal having, or at risk of having idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

In another aspect the present invention provides expression inhibitory agents for use in the treatment, and/or prophylaxis of a fibrotic condition. In a specific embodiment, said fibrotic condition is selected from idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

In yet another aspect, the present invention provides expression inhibitory agents, or a pharmaceutical composition comprising said expression inhibitory agents for use in the manufacture of a medicament for the treatment, or prophylaxis of a fibrotic condition. In a specific embodiment, said fibrotic condition is selected from idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis, Peyronie's disease, and/or diseases associated with differentiation of macrophages into M2 macrophages. In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

A particular regimen of the present method comprises the administration to a subject suffering from a fibrotic disease involving differentiation of macrophages into M2 macrophages, of an effective amount of an expression inhibitory agent for a period of time sufficient to reduce the level of abnormal fibrosis in the subject, and preferably terminate the processes responsible for said fibrotic condition. A special embodiment of the method comprises administering of an effective amount of an antibody or a fragment thereof which specifically binds to a TARGET polypeptide to a subject patient suffering from or susceptible to the development of a fibrotic disease, for a period of time sufficient to reduce or prevent, respectively, fibrotic condition in said patient, and preferably terminate, the processes responsible for said fibrotic condition In particular embodiment said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into M2 macrophages.

Another aspect of the present invention relates to compositions, comprising a DNA expression vector capable of expressing a polynucleotide capable of inhibition of expression of a TARGET polypeptide and described as an expression inhibitory agent.

The present invention provides compounds, compositions, and methods useful for modulating the expression of the TARGET genes, specifically those TARGET genes associated with a fibrotic disease and for treating such conditions by RNA interference (RNAi) using small nucleic acid molecules. In particular, the instant invention features small nucleic acid molecules, i.e., short interfering nucleic acid (siNA) molecules including, but not limited to, short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), short hairpin RNA (shRNA) and circular RNA molecules and methods used to modulate the expression of the TARGET genes and/or other genes involved in pathways of the TARGET gene expression and/or activity.

A particular aspect of these compositions and methods relates to the down-regulation or blocking of the expression of the TARGET by the induced expression of a polynucleotide encoding an intracellular binding protein that is capable of selectively interacting with the TARGET. An intracellular binding protein includes any protein capable of selectively interacting, or binding, with the polypeptide in the cell in which it is expressed and neutralizing the function of the polypeptide. Preferably, the intracellular binding protein is a neutralizing antibody or a fragment of a neutralizing antibody having binding affinity to an epitope of a TARGET selected from the group consisting of SEQ ID NO: 26-50. More preferably, the intracellular binding protein is a single chain antibody.

Antibodies according to the invention may be delivered as a bolus only, infused over time or both administered as a bolus and infused over time. Those skilled in the art may employ different formulations for polynucleotides than for proteins. Similarly, delivery of polynucleotides or polypeptides will be specific to particular cells, conditions, locations, etc.

A particular embodiment of this composition comprises the expression-inhibiting agent selected from the group consisting of antisense RNA, antisense oligodeoxynucleotide (ODN), a ribozyme that cleaves the polyribonucleotide coding for a TARGET selected from the group consisting of SEQ ID NO: 1-25, a small interfering RNA (siRNA), and a microRNA that is sufficiently homologous to a portion of the polyribonucleotide coding for a TARGET selected from the group consisting of SEQ ID NO: 1-25, such that the siRNA or microRNA interferes with the translation of the TARGET polyribonucleotide to the TARGET polypeptide.

The polynucleotide expressing the expression-inhibiting agent, or a polynucleotide expressing the TARGET polypeptide in cells, is particularly included within a vector. The polynucleic acid is operably linked to signals enabling expression of the nucleic acid sequence and is introduced into a cell utilizing, preferably, recombinant vector constructs, which will express the antisense nucleic acid once the vector is introduced into the cell. A variety of viral-based systems are available, including adenoviral, retroviral, adeno-associated viral, lentiviral, herpes simplex viral or a sendaiviral vector systems, and all may be used to introduce and express polynucleotide sequence for the expression-inhibiting agents or the polynucleotide expressing the TARGET polypeptide in the target cells.

Particularly, the viral vectors used in the methods of the present invention are replication defective. Such replication defective vectors will usually pack at least one region that is necessary for the replication of the virus in the infected cell. These regions can either be eliminated (in whole or in part), or be rendered non-functional by any technique known to a person skilled in the art. These techniques include the total removal, substitution, partial deletion or addition of one or more bases to an essential (for replication) region. Such techniques may be performed in vitro (on the isolated DNA) or in situ, using the techniques of genetic manipulation or by treatment with mutagenic agents. Preferably, the replication defective virus retains the sequences of its genome, which are necessary for encapsidating, the viral particles.

In a preferred embodiment, the viral element is derived from an adenovirus. Preferably, the vehicle includes an adenoviral vector packaged into an adenoviral capsid, or a functional part, derivative, and/or analogue thereof. Adenovirus biology is also comparatively well known on the molecular level. Many tools for adenoviral vectors have been and continue to be developed, thus making an adenoviral capsid a preferred vehicle for incorporating in a library of the invention. An adenovirus is capable of infecting a wide variety of cells. However, different adenoviral serotypes have different preferences for cells. To combine and widen the target cell population that an adenoviral capsid of the invention can enter in a preferred embodiment, the vehicle includes adenoviral fiber proteins from at least two adenoviruses. Preferred adenoviral fiber protein sequences are serotype 17, 45 and 51. Techniques or construction and expression of these chimeric vectors are disclosed in US 2003/0180258 and US 2004/0071660, hereby incorporated by reference.

In a preferred embodiment, the nucleic acid derived from an adenovirus includes the nucleic acid encoding an adenoviral late protein or a functional part, derivative, and/or analogue thereof. An adenoviral late protein, for instance an adenoviral fiber protein, may be favorably used to target the vehicle to a certain cell or to induce enhanced delivery of the vehicle to the cell. Preferably, the nucleic acid derived from an adenovirus encodes for essentially all adenoviral late proteins, enabling the formation of entire adenoviral capsids or functional parts, analogues, and/or derivatives thereof. Preferably, the nucleic acid derived from an adenovirus includes the nucleic acid encoding adenovirus E2A or a functional part, derivative, and/or analogue thereof. Preferably, the nucleic acid derived from an adenovirus includes the nucleic acid encoding at least one E4-region protein or a functional part, derivative, and/or analogue thereof, which facilitates, at least in part, replication of an adenoviral derived nucleic acid in a cell. The adenoviral vectors used in the examples of this application are exemplary of the vectors useful in the present method of treatment invention.

Certain embodiments of the present invention may use retroviral vector systems. Retroviruses are integrating viruses that infect dividing cells, and their construction is known in the art. Retroviral vectors can be constructed from different types of retrovirus, such as, MoMuLV (“murine Moloney leukemia virus”) MSV (“murine Moloney sarcoma virus”), HaSV (“Harvey sarcoma virus”); SNV (“spleen necrosis virus”); RSV (“Rous sarcoma virus”) and Friend virus. Lentiviral vector systems may also be used in the practice of the present invention.

In other embodiments of the present invention, adeno-associated viruses (“AAV”) are utilized. The AAV viruses are DNA viruses of relatively small size that integrate, in a stable and site-specific manner, into the genome of the infected cells. They are able to infect a wide spectrum of cells without inducing any effects on cellular growth, morphology or differentiation, and they do not appear to be involved in human pathologies.

As discussed hereinabove, recombinant viruses may be used to introduce DNA encoding polynucleotide agents useful in the present invention. Recombinant viruses according to the invention are generally formulated and administered in the form of doses of between about 104 and about 1014 pfu. In the case of AAVs and adenoviruses, doses of from about 106 to about 1011 pfu are particularly used. The term pfu (“plaque-forming unit”) corresponds to the infective power of a suspension of virions and is determined by infecting an appropriate cell culture and measuring the number of plaques formed. The techniques for determining the pfu titre of a viral solution are well documented in the prior art.

In the vector construction, the polynucleotide agents of the present invention may be linked to one or more regulatory regions. Selection of the appropriate regulatory region or regions is a routine matter, within the level of ordinary skill in the art. Regulatory regions include promoters, and may include enhancers, suppressors, etc.

Promoters that may be used in the expression vectors of the present invention include both constitutive promoters and regulated (inducible) promoters. The promoters may be prokaryotic or eukaryotic depending on the host. Among the prokaryotic (including bacteriophage) promoters useful for practice of this invention are lac, lacZ, T3, T7, lambda P_(r), P₁, and trp promoters. Among the eukaryotic (including viral) promoters useful for practice of this invention are ubiquitous promoters (e.g. HPRT, vimentin, actin, tubulin), therapeutic gene promoters (e.g. MDR type, CFTR, factor VIII), tissue-specific promoters, including animal transcriptional control regions, which exhibit tissue specificity and have been utilized in transgenic animals, e.g. chymase gene control region which is active in mast cells (Liao et al., (1997), Journal of Biological Chemistry, 272: 2969-2976), immunoglobulin gene control region which is active in lymphoid cells (Grosschedl, et al. (1984) Cell 38:647-58; Adames, et al. (1985) Nature 318:533-8; Alexander, et al. (1987) Mol. Cell. Biol. 7:1436-44), mouse mammary tumor virus control region which is active in testicular, breast, lymphoid and mast cells (Leder, et al. (1986) Cell 45:485-95), beta-globin gene control region which is active in myeloid cells (Mogram, et al. (1985) Nature 315:338-40; Kollias, et al. (1986) Cell 46:89-94), the CMV promoter and the Visna LTR (Sidiropoulos et al., (2001), Gene Therapy, 8:223-231)

Other promoters which may be used in the practice of the invention include promoters which are preferentially activated in dividing cells, promoters which respond to a stimulus (e.g. steroid hormone receptor, retinoic acid receptor), tetracycline-regulated transcriptional modulators, cytomegalovirus immediate-early, retroviral LTR, metallothionein, SV-40, Ela, and MLP promoters. Further promoters which may be of use in the practice of the invention include promoters which are active and/or expressed in macrophages or other cell types contributing to inflammation such as dendritic cells, monocytes, neutrophils, mast cells, endothelial cells, epithelial cells, muscle cells, etc.

Additional vector systems include the non-viral systems that facilitate introduction of polynucleotide agents into a patient. For example, a DNA vector encoding a desired sequence can be introduced in vivo by lipofection. Synthetic cationic lipids designed to limit the difficulties encountered with liposome-mediated transfection can be used to prepare liposomes for in vivo transfection of a gene encoding a marker (Feigner, et. al. (1987) Proc. Natl. Acad Sci. USA 84:7413-7); see Mackey, et al. (1988) Proc. Natl. Acad. Sci. USA 85:8027-31; Ulmer, et al. (1993) Science 259:1745-8). The use of cationic lipids may promote encapsulation of negatively charged nucleic acids, and also promote fusion with negatively charged cell membranes (Feigner and Ringold, (1989) Nature 337:387-8). Particularly useful lipid compounds and compositions for transfer of nucleic acids are described in International Patent Publications WO 95/18863 and WO 96/17823, and in U.S. Pat. No. 5,459,127. The use of lipofection to introduce exogenous genes into the specific organs in vivo has certain practical advantages and directing transfection to particular cell types would be particularly advantageous in a tissue with cellular heterogeneity, for example, pancreas, liver, kidney, and the brain. Lipids may be chemically coupled to other molecules for the purpose of targeting. Targeted peptides, e.g., hormones or neurotransmitters, and proteins for example, antibodies, or non-peptide molecules could be coupled to liposomes chemically. Other molecules are also useful for facilitating transfection of a nucleic acid in vivo, for example, a cationic oligopeptide (e.g., International Patent Publication WO 95/21931), peptides derived from DNA binding proteins (e.g., International Patent Publication WO 96/25508), or a cationic polymer (e.g., International Patent Publication WO 95/21931).

It is also possible to introduce a DNA vector in vivo as a naked DNA plasmid (see U.S. Pat. Nos. 5,693,622, 5,589,466 and 5,580,859). Naked DNA vectors for therapeutic purposes can be introduced into the desired host cells by methods known in the art, e.g., transfection, electroporation, microinjection, transduction, cell fusion, DEAE dextran, calcium phosphate precipitation, use of a gene gun, or use of a DNA vector transporter (see, e.g., Wilson, et al. (1992) J. Biol. Chem. 267:963-7; Wu and Wu, (1988) J. Biol. Chem. 263:14621-4; Hartmut, et al. Canadian Patent Application No. 2,012,311, filed Mar. 15, 1990; Williams, et al (1991). Proc. Natl. Acad. Sci. USA 88:2726-30). Receptor-mediated DNA delivery approaches can also be used (Curiel, et al. (1992) Hum. Gene Ther. 3:147-54; Wu and Wu, (1987) J. Biol. Chem. 262:4429-32).

A biologically compatible composition is a composition, that may be solid, liquid, gel, or other form, in which the compound, polynucleotide, vector, and antibody of the invention is maintained in an active form, e.g., in a form able to effect a biological activity. For example, a compound of the invention would have inverse agonist or antagonist activity on the TARGET; a nucleic acid would be able to replicate, translate a message, or hybridize to a complementary mRNA of the TARGET; a vector would be able to transfect a target cell and express the antisense, antibody, ribozyme or siRNA as described hereinabove; an antibody would bind a the TARGET polypeptide domain.

A particular biologically compatible composition is an aqueous solution that is buffered using, e.g., Tris, phosphate, or HEPES buffer, containing salt ions. Usually the concentration of salt ions will be similar to physiological levels. Biologically compatible solutions may include stabilizing agents and preservatives. In a more preferred embodiment, the biocompatible composition is a pharmaceutically acceptable composition. Such compositions can be formulated for administration by topical, oral, parenteral, intranasal, subcutaneous, and intraocular, routes. Parenteral administration is meant to include intravenous injection, intramuscular injection, intraarterial injection or infusion techniques. The composition may be administered parenterally in dosage unit formulations containing standard, well-known non-toxic physiologically acceptable carriers, adjuvants and vehicles as desired.

Pharmaceutical compositions for oral administration can be formulated using pharmaceutically acceptable carriers well known in the art in dosages suitable for oral administration. Such carriers enable the pharmaceutical compositions to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions, and the like, for ingestion by the patient. Pharmaceutical compositions for oral use can be prepared by combining active compounds with solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are carbohydrate or protein fillers, such as sugars, including lactose, sucrose, mannitol, or sorbitol; starch from corn, wheat, rice, potato, or other plants; cellulose, such as methyl cellulose, hydroxypropylmethyl-cellulose, or sodium carboxymethyl-cellulose; gums including arabic and tragacanth; and proteins such as gelatin and collagen. If desired, disintegrating or solubilizing agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, alginic acid, or a salt thereof, such as sodium alginate. Dragee cores may be used in conjunction with suitable coatings, such as concentrated sugar solutions, which may also contain gum arabic, talc, polyvinyl-pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for product identification or to characterize the quantity of active compound, i.e., dosage.

Pharmaceutical preparations that can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a coating, such as glycerol or sorbitol. Push-fit capsules can contain active ingredients mixed with filler or binders, such as lactose or starches, lubricants, such as talc or magnesium stearate, and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid, or liquid polyethylene glycol with or without stabilizers.

Particular sterile injectable preparations can be a solution or suspension in a non-toxic parenterally acceptable solvent or diluent. Examples of pharmaceutically acceptable carriers are saline, buffered saline, isotonic saline (for example, monosodium or disodium phosphate, sodium, potassium; calcium or magnesium chloride, or mixtures of such salts), Ringer's solution, dextrose, water, sterile water, glycerol, ethanol, and combinations thereof 1,3-butanediol and sterile fixed oils are conveniently employed as solvents or suspending media. Any bland fixed oil can be employed including synthetic mono- or di-glycerides. Fatty acids such as oleic acid also find use in the preparation of injectables.

The compounds or compositions of the invention may be combined for administration with or embedded in polymeric carrier(s), biodegradable or biomimetic matrices or in a scaffold. The carrier, matrix or scaffold may be of any material that will allow composition to be incorporated and expressed and will be compatible with the addition of cells or in the presence of cells. Particularly, the carrier matrix or scaffold is predominantly non-immunogenic and is biodegradable. Examples of biodegradable materials include, but are not limited to, polyglycolic acid (PGA), polylactic acid (PLA), hyaluronic acid, catgut suture material, gelatin, cellulose, nitrocellulose, collagen, albumin, fibrin, alginate, cotton, or other naturally-occurring biodegradable materials. It may be preferable to sterilize the matrix or scaffold material prior to administration or implantation, e.g., by treatment with ethylene oxide or by gamma irradiation or irradiation with an electron beam. In addition, a number of other materials may be used to form the scaffold or framework structure, including but not limited to: nylon (polyamides), dacron (polyesters), polystyrene, polypropylene, polyacrylates, polyvinyl compounds (e.g., polyvinylchloride), polycarbonate (PVC), polytetrafluorethylene (PTFE, teflon), thermanox (TPX), polymers of hydroxy acids such as polylactic acid (PLA), polyglycolic acid (PGA), and polylactic acid-glycolic acid (PLGA), polyorthoesters, polyanhydrides, polyphosphazenes, and a variety of polyhydroxyalkanoates, and combinations thereof. Matrices suitable include a polymeric mesh or sponge and a polymeric hydrogel. In the particular embodiment, the matrix is biodegradable over a time period of less than a year, more particularly less than six months, most particularly over two to ten weeks. The polymer composition, as well as method of manufacture, can be used to determine the rate of degradation. For example, mixing increasing amounts of polylactic acid with polyglycolic acid decreases the degradation time. Meshes of polyglycolic acid that can be used can be obtained commercially, for instance, from surgical supply companies (e.g., Ethicon, N.J.). In general, these polymers are at least partially soluble in aqueous solutions, such as water, buffered salt solutions, or aqueous alcohol solutions, that have charged side groups, or a monovalent ionic salt thereof.

The composition medium can also be a hydrogel, which is prepared from any biocompatible or non-cytotoxic homo- or hetero-polymer, such as a hydrophilic polyacrylic acid polymer that can act as a drug absorbing sponge. Certain of them, such as, in particular, those obtained from ethylene and/or propylene oxide are commercially available. A hydrogel can be deposited directly onto the surface of the tissue to be treated, for example during surgical intervention.

Embodiments of pharmaceutical compositions of the present invention comprise a replication defective recombinant viral vector encoding the agent of the present invention and a transfection enhancer, such as poloxamer. An example of a poloxamer is Poloxamer 407, which is commercially available (BASF, Parsippany, N.J.) and is a non-toxic, biocompatible polyol. A poloxamer impregnated with recombinant viruses may be deposited directly on the surface of the tissue to be treated, for example during a surgical intervention. Poloxamer possesses essentially the same advantages as hydrogel while having a lower viscosity.

The active agents may also be entrapped in microcapsules prepared, for example, by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsules and poly-(methylmethacylate) microcapsules, respectively, in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano-particles and nanocapsules) or in macroemulsions. Such techniques are disclosed in Remington's Pharmaceutical Sciences (1980) 16th edition, Osol, A. Ed.

Sustained-release preparations may be prepared. Suitable examples of sustained-release preparations include semi-permeable matrices of solid hydrophobic polymers containing the antibody, which matrices are in the form of shaped articles, for example, films, or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and gamma-ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the LUPRON DEPOT™. (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), and poly-D-(−)-3-hydroxybutyric acid. While polymers such as ethylene-vinyl acetate and lactic acid-glycolic acid enable release of molecules for over 100 days, certain hydrogels release proteins for shorter time periods. When encapsulated antibodies remain in the body for a long time, they may denature or aggregate as a result of exposure to moisture at 37° C., resulting in a loss of biological activity and possible changes in immunogenicity. Rational strategies can be devised for stabilization depending on the mechanism involved. For example, if the aggregation mechanism is discovered to be intermolecular S—S bond formation through thio-disulfide interchange, stabilization may be achieved by modifying sulfhydryl residues, lyophilizing from acidic solutions, controlling moisture content, using appropriate additives, and developing specific polymer matrix compositions.

As used herein, therapeutically effective dose means that amount of protein, polynucleotide, peptide, or its antibodies, agonists or antagonists, which ameliorate the symptoms or condition. Therapeutic efficacy and toxicity of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, for example, ED₅₀ (the dose therapeutically effective in 50% of the population) and LD₅₀ (the dose lethal to 50% of the population). The dose ratio of toxic to therapeutic effects is the therapeutic index, and it can be expressed as the ratio, LD₅₀/ED₅₀. Pharmaceutical compositions that exhibit large therapeutic indices are particular. The data obtained from cell culture assays and animal studies are used in formulating a range of dosage for human use. The dosage of such compounds lies particularly within a range of circulating concentrations that include the ED₅₀ with little or no toxicity. The dosage varies within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.

For any compound, the therapeutically effective dose can be estimated initially either in cell culture assays or in animal models, usually mice, rabbits, dogs, or pigs. The animal model is also used to achieve a desirable concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. The exact dosage is chosen by the individual physician in view of the patient to be treated. Dosage and administration are adjusted to provide sufficient levels of the active moiety or to maintain the desired effect. Additional factors which may be taken into account include the severity of the disease state, age, weight and gender of the patient; diet, desired duration of treatment, method of administration, time and frequency of administration, drug combination(s), reaction sensitivities, and tolerance/response to therapy. Long acting pharmaceutical compositions might be administered every 3 to 4 days, every week, or once every two weeks depending on half-life and clearance rate of the particular formulation.

The pharmaceutical compositions according to this invention may be administered to a subject by a variety of methods. They may be added directly to targeted tissues, complexed with cationic lipids, packaged within liposomes, or delivered to targeted cells by other methods known in the art. Localized administration to the desired tissues may be done by direct injection, transdermal absorption, catheter, infusion pump or stent. The DNA, DNA/vehicle complexes, or the recombinant virus particles are locally administered to the site of treatment. Alternative routes of delivery include, but are not limited to, intravenous injection, intramuscular injection, subcutaneous injection, aerosol inhalation, oral (tablet or pill form), topical, systemic, ocular, intraperitoneal and/or intrathecal delivery. Examples of ribozyme delivery and administration are provided in Sullivan et al. WO 94/02595.

Administration of an expression-inhibiting agent or an antibody of the present invention to the subject patient includes both self-administration and administration by another person. The patient may be in need of treatment for an existing disease or medical condition, or may desire prophylactic treatment to prevent or reduce the risk for diseases and medical conditions affected by differentiation of macrophages into alternatively-activated macrophages. The expression-inhibiting agent of the present invention may be delivered to the subject patient orally, transdermally, via inhalation, injection, nasally, rectally or via a sustained release formulation.

In Vitro Methods

The present invention also provides an in vitro method of reducing or inhibiting the differentiation of macrophages into M2 macrophages, said method comprising contacting a population of macrophage cells with an inhibitor of the activity or expression of a TARGET polypeptide. In a particular embodiment said inhibitor is an antibody. In an alternative embodiment said antibody is a monoclonal antibody

The present invention further relates to an in vitro method of inhibiting the differentiation of macrophages into M2 macrophages, said method comprising contacting a population of macrophage cells with an inhibitor selected from the group consisting of an antisense polynucleotide, a ribozyme, a small interfering RNA (siRNA) and a short-hairpin RNA (shRNA), wherein said inhibitor comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a nucleic acid encoding a TARGET polypeptide.

The down regulation of gene expression using antisense nucleic acids can be achieved at the translational or transcriptional level. Antisense nucleic acids of the invention are particularly nucleic acid fragments capable of specifically hybridizing with all or part of a nucleic acid encoding a TARGET polypeptide or the corresponding messenger RNA. In addition, antisense nucleic acids may be designed which decrease expression of the nucleic acid sequence capable of encoding a TARGET polypeptide by inhibiting splicing of its primary transcript. Any length of antisense sequence is suitable for practice of the invention so long as it is capable of down-regulating or blocking expression of a nucleic acid coding for a TARGET. Particularly, the antisense sequence is at least about 15-30, and particularly at least 17 nucleotides in length. The preparation and use of antisense nucleic acids, DNA encoding antisense RNAs and the use of oligo and genetic antisense is known in the art.

Examples

The invention is further illustrated using examples provided below. It would be obvious to a person skilled in the art that the examples might be easily modified or adapted to particular types of conditions, scale or cell types using routine adaptations.

Example 1 describes the M2 screening assay.

Example 2 describes the M2 re-screen.

Example 3 describes the M1 counter assay.

Example 4 describes the M2 assay using CD206 marker.

Example 5 describes on target and toxicity assessment of selected shRNA constructs.

Example 6 describes infection units (IU)-based on target screen and toxicity assessment of selected shRNA constructs.

Example 7 describes the analysis of expression of TARGETs in macrophages.

Example 1 Screening Adenoviral Library Using the M2 Macrophage Differentiation Assay 1.1 Background of the Assay

M2 macrophages can be generated by priming M0 macrophages derived from human peripheral monocytes with a combination of IL-4 and IL-10. The polarized M2 macrophages express high levels of secreted CCL18 and the surface-bound markers CD163 and CD206. Furthermore, a person of skill in the art will appreciate that several positive controls may also be selected based on available literature on the signaling pathway of IL-4 and IL-10 and the read-out, CCL18.

1.2 Cell Cultures

To obtain M0 macrophages, buffy coats from healthy donors and not older than 50 years, were purchased via the blood bank (Sanquin, The Netherlands) for isolation of peripheral blood mononuclear cells PBMCs. The isolation was performed using a Ficoll-Paque PLUS gradient (GE healthcare, cat#17-1440-03) and subsequently the CD14+ monocytes were extracted using CD14 MicroBeads (Miltenyi, cat. #130-050-201). After the CD14 isolation a QC regarding the purity was performed on the isolated CD14+ fraction based on CD14 fluorescent labelled antibody staining using flow cytometric analysis (Facscalibur BD) and CellQuest Pro software.

To differentiate the CD14 positive cells into M0 macrophages, the cells were seeded in 96-well plates with RPMI Glutamax medium, containing 10% FBS, 1% P/S and 100 ng/mL M-CSF. In total four plates were seeded per donor at a cell density of 20,000 cells/well and cultured for six days. On day six, one plate from both donors containing the M0 macrophages were harvested for RNA isolation and the other three plates were refreshed. Ten days after seeding, the second plate from both donors containing M0 macrophages was harvested for RNA isolation. The other two plates from each donor were triggered with 20 ng/ml IFNγ and 5 ng/mL IFNγ or 20 ng/mL IL-10 and 20 ng/mL LPS in RPMI Glutamax medium containing 10% FBS and 1% P/S, to generate M1 or M2, respectively. The cells were cultured for another three days before the macrophages were harvested for RNA isolation. After harvest, specific cell markers were tested using flow cytometry to confirm the M0, M1 and M2 phenotypes. This was done by assessing the expression markers CD163 and CD206. The CD163 and CD206 expression were enhanced in the M2 macrophages and decreased in the M1 macrophages compared to the M0 macrophages, in both donors.

1.3 Positive and Negative Controls

STAT6_v5 was used together with CCL18_v1, IL-4R_v6, JAK1_v23 and STAT6_v6 as positive controls, based on public available resources (for example, Sica et al, 2012) regarding the IL-10 and IL-4 pathway. Ffluc_v19, ffluc_v24 and luc_v13 are shRNA against non-expressed genes (firefly luciferase and luciferase, respectively) and were used as negative controls.

TABLE 2 Overview of the knock-down sequences of the controls in M2 macrophage assay Control code Control name Sequence SEQ ID NO N1 luc_v13 GGTTACCTAAGGGTGTGGC 51 N2 ffluc_v19 GAATCGATATTGTTACAAC 52 N3 ffluc_v24 GCATAAGGCTATGAAGAGA 53 P1 CCL18_v1 GTCTATACCTCCTGGCAGA 54 P2 STAT6_v5 GCCAAAGACCTGTCCATTC 55 P3 STAT6_v6 GTCCCAGCTACCATCAAGA 56 P4 IL4R_v6 CCCGGCAGATTTCAGAATC 57 P5 JAK1_v23 GAGTCTGTGGTCAGCATTA 58

1.4 CCL18 384-Well Luminescent ELISA

The CCL18 detection assay using high binding MSD plates was developed and automated. The antibody pair used in the commercial CCL18 ELISA was used with a 384-well Meso Scale Discovery (MSD) assay (see: http://www.mesoscale.com/CatalogSystemWeb/WebRoot/technology/ecl/walkthrough.htm), for an overview of the MSD technology). Automation was performed on the Bravo system (Agilent). Automation was performed using the Bravo system. White 384-well high binding plates (Lumitrac 600, Greiner Bio-one) were used and coated with CCL18 capture antibody (Human CCL18/PARC MAb (Clone 64507), Mouse IgG1, R&D Systems) in PBS incubated o/n at 4° C. The plates were blocked with 5% BSA in PBS-Tween at RT for one hour. After blocking and washing of the plates, a single concentration of CCL18 and a standard curve was added to the plate and incubated for two hours at RT. Hereafter, the plates were washed and incubated with biotin labeled CCL18 detection antibody (CCL18/PARC Biotinylated Affinity Purified PAb, Goat IgG, R&D Systems). Subsequently, the plates were washed three times in wash buffer (PBS-Tween) and incubated with Streptavidin-HRP (Cat# DY998, R&D Systems) in reagent buffer (1% BSA in PBS-Tween). After 30 minutes incubation at room temperature while shaking, the plates were washed three times in wash buffer before luminescent substrate (BM Chemiluminescence ELISA Substrate (HRP), Roche) was added which prepared 15 minutes in advance. After approximately five minutes the plates were measured on an Envision machine (PerkinElmer) using Victor Wallac software.

1.5 Screening Protocol

The primary screen was performed using shRNA constructs comprising the complete adenoviral shRNA library (12210 shRNA constructs designed against 4438 genes). The library consisted of 34×384-well plates and the screen was performed in biological duplicate. MO14 was chosen based on the pilot screen. All individual 384-well source plates contained 12 negative and 20 positive control viruses positioned in column 13 and 14 (FIG. 1). Additional QC plates were also measured. The QC plates contained only the control viruses positioned in column 13 and 14 in order to determine the sample dilution factor. The remainder of the wells consisted of cells that were not transduced with adenovirus to assess the performance of the negative controls and the intra-plate variation. In total three dilutions were made of the QC samples from all three donors used (donor CQ, CR and CU). Column 21 was used for the CCL18 standard, to determine the optimal dilution factor for each donor separately. Three out of the five positive controls should give more than 40% inhibition compared to the negative controls. The set-up of the protocol is outline in FIG. 2.

To perform the screen, 5,000 CD14+ cells/well were seeded in 384-well culture plates on day 0 with RPMI Glutamax medium (cat #: 1870-010), containing 10% fetal bovine serum (FBS), 1% penicillin/streptomycin P/S and 100 ng/mL Macrophage colony stimulating factor (M-CSF). After five days, the M0 macrophages were transduced with the adenoviruses followed by a refreshment step one day later. On day ten the cells were primed with RPMI Glutamax medium containing 10% FBS, 1% P/S, 20 ng/mL IL-4 and 20 ng/mL IL-10 to trigger the cells to differentiate into M2 macrophages. Medium was harvested on day 13 and secreted CCL18 was detected using a CCL18 384-well luminescent ELISA (as described in 1.4) after measuring a QC plate to determine sample dilution.

1.6 QC, Data Analysis and Hit Identification

The sample population had a non-Gaussian distribution based on a Shapiro-Wilk test and normalization was required. The robust Z-score was used, that utilizes median and median absolute deviation (MAD) instead of the mean and SD (Zhang et al., 2006). This normalization method is less sensitive to extreme values and asymmetry in the distribution and therefore suitable for the skewed sample distribution observed with the raw data points. Potential plate effects were assessed using the heat maps.

To correct for these positional effects a normalization method, similar to the robust Z-score was used. The method is referred as the B-score and attempts to correct for possible plate edge/row/column effects and the plate center effect. The calculation is similar to the robust Z-score, except for the median calculation that is replaced by median value of the plate adjusted for each well separately depending on its position on the plate (Malo et al. 2006).

After calculating the B-score, the control and sample performance was determined for each plate separately and compared to each other. To assess the performance of the duplicate values, the Spearman correlation coefficient based on the sample values was calculated. Based on the performance of the positive controls and the negative controls, a B-score cut-off was selected for hit calling. Kappa statistics was used as a statistical measure of inter-replicate agreement of the hits after hit calling.

1.7 Results

On all three QC plates the untransduced samples showed little intra-plate variation (data not shown) and the negative controls remained within the 25% reduction and induction range compared to the no virus control.

The average Spearman correlation coefficient of the primary screen was 0.87, ranging from 0.81 till 0.92 per plate pair.

A B-score cut-off of −1.3 was used for hit calling (FIG. 3A). Four plates were analyzed separately and a cut-off of −0.95 was used for hit calling (FIG. 3B). With these cut-offs none of the negative controls were identified as a hit and more than 95% of the positive controls were identified as a hit.

In total 999 shRNA hits were identified in the primary screen with an average kappa value of 0.80 on the plates with a cut-off of −1.3 and an average kappa value of 0.72 on the plates with a cut-off of −0.95. An overview of the assay statistical analysis is shown in Table 3. In this table the assay performance is summarized.

TABLE 3 Assay parameters overview of the primary screen. Average # source Hit Average Range Average Readout Cut-off plates rate (%) Spearman Spearman Kappa CCL18 −1.30 33 8.4 0.87 0.81-0.92 0.80 CCL18 −0.95 2 7.5 0.72

Example 2. Re-Screen of Identified Hits Using M2 Macrophage Differentiation Assay 2.1 Background

The primary screen was followed by the rescreen for which the same assay set up was used as described in Example 1. The 999 viruses identified in the primary M2 macrophage differentiation screen (Example 1) were further evaluated in the rescreen. For the rescreen a different transduction plate layout was designed. In this layout the outer wells were omitted and the negative controls were arranged in such a way to allow detection of possible plate effects. Furthermore, >30% of the plate content consisted of negative controls as the hit calling analysis is performed based on the mean of the negative controls. All identified hits from the primary screen were repropagated and were distributed randomly over the plate

The adenoviral shRNA constructs from the adenoviral library that were identified as a hit in the primary screen of Example 1 as well as the same control viruses were re-propagated for the rescreen. The new propagations of the controls (same controls were used as in the Example 1) and a representative part of the hit set were tested in the pilot rescreen to assess the quality of the viruses and to establish an optimal transduction volume for the rescreen. Similar criteria as used as for development of the primary screen

2.2 Re-Screen Protocol

The rescreen consisted of eight 384-well plates and was performed in biological duplicate, at MO14 in one donor. The cells were obtained according to the same protocol as in Example 1. All individual 384-well source plates contained 80 negative and 12 positive control viruses distributed over the plate as shown in FIG. 4. The assay set up was identical to the primary M2 macrophage differentiation screen (see Example 1). A QC plate was included in the assay, containing only the controls according to the plate layout. The QC plate was used to determine the dilution factor for the supernatant in which the CCL18 secretion was measured. The samples were diluted 1:37.5.

2.3 Data Analysis

Normalization of the data was done using the Robust Z score based on the mean negative controls. The robust Z score based on negatives, is calculated by dividing the readout value minus the median of the negative controls by the MAD (median absolute deviation) of the negative controls. To assess the performance of the duplicate values, the Spearman correlation coefficient based on the sample values was calculated.

2.4 Results

In FIG. 5 the control and sample performance of the rescreen is shown, in which a clear separation of the positive and negative controls can be seen. A strong correlation between the duplicate data points was observed with an average Spearman of 0.93, ranging from 0.91 till 0.96 per duplicate plate. Based on the performance of the positive controls compared to the negative controls, a B-score cut-off of −1.3 was used for hit calling. With this cut-off none of the negative controls were identified as a hit and 100% of the positive controls were identified as a hit.

The rescreen was performed successfully and with a cut-off of −1.3 resulted in 619 hits. After QC and thorough analysis, these 619 hits represent 616 genes and are designated confirmed candidate TARGETs (Table 4). Based on the rescreen, 616 genes were taken forward for the validation phase.

TABLE 4 Assay parameters overview of the rescreen. Cut-off B- # Source Confirmation # Average Readout score plates rate % Hits Spearman CCL18 −1.30 8 58 619 0.93 (0.91-0.96)

Example 3 M1 Counter Assay 3.1 Background of the Assay

600 confirmed candidate TARGETs were identified in the primary screen and rescreen that inhibitions of which inhibited differentiation of macrophages into M2 macrophages (Example 1 and 2). To assess that these shRNA do not interfere with development of classically activated M1 macrophages, a M1 counter screen can be developed to exclude the shRNA constructs inhibiting expression of targets which in turn inhibit the M1 phenotype.

A hallmark of M1 macrophages is the secretion of TNFα (Mantovani, 2004). The expression of TNFα upon triggering with LPS and IFN′ (known to polarize macrophages to the M1 phenotype), allows the M1 macrophages to be distinguished from M0 and M2 macrophages. Hence, a M1 counter screen might be performed in which secreted TNFα can be used as a read-out. To establish a robust and reproducible M1 counter assay the following aspects should be assessed: determination of TNFα secretion, optimization of the M1 counter screen assay, and selection of positive and negative controls.

3.2 Cell Donors and Cell Protocol

To obtain macrophages, buffy coats from healthy donors were purchased via the blood bank (Sanquin, The Netherlands) for isolation of peripheral blood mononuclear cells PBMCs. The isolation was performed using a Ficoll-Paque gradient (GE healthcare) and subsequently the CD14+ cells were extracted using CD14 MicroBeads (Miltenyi, cat. #130-050-201). After the CD14 isolation a QC regarding the purity was performed on the PBMCs and the isolated CD14+ fraction using flow cytometric analysis (Facscalibur BD) and CellQuest Pro software with CD14 fluorescent labelled antibody staining

3.3 TNFα HTRF Assay

The secreted TNFα was measured using the homogeneous time-resolved fluorescence (HTRF) technique according to manufacturers' protocol (Cisbio Bioassays, cat. #: 62TNFPEC). The signal was measured on an envision machine (Perkin Elmer) at 665 and 620 nm and analyzed using Victor Wallac software. A calibration curve was used to correlate the raw fluorescent signals to the TNFα concentration.

To confirm the specificity of the read-out, the secretion of TNFα by M1 macrophages was compared to the secretion by M2 macrophages. The TNFα secretion by M1 macrophages was strongly enhanced, whereas in supernatants obtained from M2 macrophages TNFα could not be detected. The TNFα HTRF was therefore suitable to distinguish M1 macrophages from M2 macrophages.

3.4 Positive and Negative Controls

In addition to the positive control virus TNF_v12, a selection of new putative positive controls, targeting genes in the M1 pathway (MYD88, TLR4, NFKB1, TRAF6 and TNFα) was assessed for TNFα inhibition to further validate the M1 counter screen. The TRAF6_v4 positive control showed more than 60% inhibition in donor EK and treatment with the TNF_v9 positive control resulted in more than 40% TNFα reduction in donor EK. The MYD88_v4 positive control showed around 40% inhibition in donor EL. Only the TNF_v12 positive control showed in both donors over 60% inhibition compared to the average of the negative controls. All these positive controls were taken forward to develop M1 counter screen.

TABLE 5 Summary of the controls Control code Control name Sequence SEQ ID NO N1 luc_v13 GGTTACCTAAGGGTGTGGC 51 N2 ffluc_v19 GAATCGATATTGTTACAAC 52 N3 ffluc_v24 GCATAAGGCTATGAAGAGA 53 P1 MYD88_v4 GGAACAGACAAACTATCGA 59 P2 TRAF6_v4 GTTCTGGTCATGGATCTCT 60 P3 TNF_v12 CGTGGAGCTGAGAGATAAC 61

3.5 Set-Up of M1 Counter Assay

The experimental setup was as follows: On day 0 5,000 CD14+ cells/well were seeded in 384-well plates with medium containing M-CSF. Five days later the transduction was preformed followed by a refresh the next day. On day ten the trigger containing 20 ng/mL IFN-γ and 5 ng/mL LPS was added and refreshed on day 12. The trigger was refreshed 16 hours before harvest. The supernatants were harvested on day 13 in which the secreted TNFα was determined using a TNFα HTRF assay (FIG. 6). The M1 counter screen consisted of eight 384-well source plates similar to the viral repropagation aliquot set of the rescreen. The layout was therefore identical to that of the rescreen except for the CCL18 positive controls which were replaced by three positive controls for the TNFα read-out: MYD88_v4, TRAF6_v6 and TNF_v12 (FIG. 7). The screen was performed in two donors (donors EO and EP) at M018 in one batch. In addition, one QC plate for each donor containing only the virus controls was included in the experimental setup. These plates were assessed first, using the TNFα HTRF, to determine which donor provided the most optimal assay window.

In both donors the reduction in TNFα secretion was over 40% after transduction with the TNF_v12 positive control compared to the average of the negative controls. A different donor ET was selected for analysis of the complete set based on a slightly higher TNFα concentration as compared to donor ES.

3.6 Data Analysis

Normalization of the TNFα data was performed using the robust Z-score based on the mean negative controls. Positional effects were corrected by subsequently calculating the B-score.

The average Spearman from donor ET was 0.77, ranging from 0.70 till 0.86 per duplicate plate, indicating a strong correlation between duplicates. Based on the performance of the TNF_v12 positive controls compared to the negative controls, a B-score cut-off of >−1.3 was used for hit calling. With these cut-offs 1.67% of the negative controls were identified as a hit and 90.60% of the TNF_v12 positive controls were identified as a hit.

3.7 Results

729 hits were identified in the counter screen. Since the same virus set of the rescreen was used, and the results of the counter screen were compared with the results of the M2 macrophage differentiation rescreen (Example 1). This resulted in the identification of a total of 408 confirmed candidate TARGETs which did not affect M1 differentiation (Table 6). These 408 confirmed candidate Targets were taken forward for further validation.

TABLE 6 Results M1 counter screen Cut-off Robust # Source # Average Read-out Z-score plates Hits Spearman TNFα >−1.3 8 729 0.77 (0.70-0.86)

Example 4 M2 Assay Using CD206 Marker 4.1 Background of the Assay

To confirm that the candidate shRNA constructs inhibited M2 differentiation, a validation assay with a different read-out to the primary CCL18 read-out can be developed. Two surface markers, CD163 and CD206, are known to be expressed on M2 macrophages and can be used to distinguish between M0, M1 and M2 macrophages (Murray et al., 2011). During the M2 assay development and throughout the screening phase, both CD163 and CD206 expression levels were used for QC analysis to assess macrophage differentiation (see Example 1). M2 primed macrophages showed enhanced expression of CD163 and CD206 compared to M0 and M1 macrophages. The induction of CD206 expression upon M2 priming was more profound than CD163 and it was therefore decided to develop a validation assay with CD206 as read-out.

4.2 CD206 Detection Method (ICC)

For indirect labelling, a mouse-anti-human CD206 primary antibody (BD Pharmingen, cat. 555953) in combination with a goat-anti-mouse Alexa488 secondary antibody (Invitrogen, cat. A-11001) was used. Both the primary and secondary antibodies were tested in different dilutions to find the most optimal staining conditions.

These results were obtained when the primary antibody was used in a 1:200 dilution and the secondary antibody was used in a 1:500 dilution. The images were taken on the GE INcell Analyzer 2000 with a 10× objective in the DAPI (nuclei) and the FITC (Alexa488) channel. Using this indirect labelling the CD206 expression in M2 primed macrophages was strongly enhanced compared to M0 macrophages and reduced in the M1 macrophages.

4.3 Algorithm to Quantify CD206

To quantify the CD206 ICC staining in a high throughput screening format an algorithm was developed. The output of the algorithm should provide a representative value of the number of CD206 expressing macrophages observed in the imaged areas (FIG. 8). Based on the FACS data from previous experiments, M0, M1 and M2 macrophages all express some level of CD206. M2 macrophages could only be distinguished from M1 and M0 populations based on the enhanced expression of CD206.

The algorithm calculated the number of CD206 positive cells by using a threshold for the CD206 expression. Next, based on the nuclei count, the total number of cells in the well was determined and this number was used to determine the percentage of CD206 positive cells, i.e. M2 macrophages. By applying this algorithm percentage of M2 macrophages can be determined. It should be noted that the absolute values differed between donors, but a robust window was observed within a single donor.

4.4 Positive and Negative Controls

The three negative control viruses used in the Examples 1 and 2 were also tested in the M2 validation assay. The negative controls should not inhibit or induce the read-out more than 25% compared to the no virus control. All three negative controls fulfilled this criterion and were selected as negative controls for the M2 validation assay.

For the selection of positive controls various viruses, which target CD206 (also named Mannose Receptor C type 1 (MRC1)), were tested in the M2 validation assay. Four out of the six viruses targeting CD206 resulted in >60% reduction compared to the average of the negative controls. Two viruses, MRC1_v1 and MRC1_v2, gave the most consistent results in all donors tested and were therefore selected as positive controls for the M2 validation assay read-out.

In addition, the panel of positive controls used in Example 1 was also included in the CD206 assay. The STAT6_v5 and STAT6_v6 positive controls inhibited the percentages of CD206 more than 40% and were therefore also selected as positive controls for the M2 validation assay. The CCL18_v1 positive control did not or only minimally affect CD206 expression. This is expected as CCL18 is an end stage molecule in the IL-4/IL-10 pathway and is therefore unlikely to affect CD206 expression, except through a possible autocrine or paracrine loop.

TABLE 7 Summary of controls used in CD206 screen SEQ Control code Name Sequence ID NO N1 luc_v13 GGTTACCTAAGGGTGTGGC 51 N2 ffluc_v19 GAATCGATATTGTTACAAC 52 N3 ffluc_v24 GCATAAGGCTATGAAGAGA 53 P1 CCL18_v1 GTCTATACCTCCTGGCAGA 54 P2 IL4R_v6 CCCGGCAGATTTCAGAATC 57 P3 MRC1_v1 GACTTAGCTAGCATCAATA 62 P4 STAT6_v6 GTCCCAGCTACCATCAAGA 56 P5 JAK1_v23 GAGTCTGTGGTCAGCATTA 58 P6 MRC1_v2 GGATATTGTCCATTGAAAT 63

4.5 Toxicity Assessment Assay

A toxicity assay was developed as part of the validation to exclude false positive hits due to toxic effects. The commercially available Cell Titer Blue (CTB) reagent (Promega, cat. G8081) can be used to measure the metabolic capacity of the cells. The CTB reagent contains a dye, resazurin, which viable cells can convert into resorufin which is highly fluorescent. The CTB reagent was added to the cells in a one in five dilution either by replacing the medium or adding it directly to the medium on the cells. After 24 hours, the relative fluorescent units (RFU), representing viability, were measured on an Envision machine.

To evaluate the sensitivity of the CTB reaction in the macrophages, various cell densities were seeded and the viability was measured. This resulted in a strong correlation between number of cells and RFU signals, indicating that the assay is very sensitive and suitable for measuring cell viability in macrophages. Subsequently, the cells were treated with control virus from the shRNA adenoviral library to assess the toxicity.

To exclude false positive candidate TARGETs, the shRNA constructs from the adenoviral library should not show more than 30% cellular toxicity compared to the no virus controls. Therefore, the macrophages were treated with either no virus or a negative control virus (ffluc_v24). Additionally, staurosporin was added to the cells as a positive control for toxicity. Furthermore, the positive control IL4R_v6 was also included as a positive control since treatment with the IL4R_v6 positive control resulted in a significant decrease in nuclei counts, which indicate toxicity. This observation was done in multiple donors during assay development of the CD206 validation screen.

The RFU of the negative controls was comparable to the no virus control and therefore not toxic. In the staurosporin-treated macrophages the signal and thus viability, decreased dramatically. Treatment with the IL4R_v6 positive control induced around 30% toxicity in M0 and M2 macrophages and more than 50% in M1 macrophages.

4.6 Set-Up of the Screening Protocol for CD206 Read-Out

shRNAs against 408 candidate TARGETs, which followed from the M2 macrophage screen (Example 1) and M1 counter screen (Example 2), were tested in the M2 CD206 validation screen which consisted of thirteen 96-well virus source plates. The screen was performed in biological duplicate, at MO14. The combined protocol together with toxicity assay is presented in FIG. 9.

To perform the screen, on day 0 CD14+ cells were seeded in 96-well μclear plates with medium containing M-CSF to allow the cells to differentiate to M0 macrophages. On day five the transduction was performed followed by a refreshment of the medium one day later. On day ten the interleukins were added to obtain the M2 macrophages. Three days later the cells were fixed for the CD206 ICC assay or CTB was added to measure cytotoxicity. The shRNA adenovirus layout and the experimental setup were identical to the pilot screen, except for column one were staurosporin was added on day 12 to induce toxicity (FIG. 9).

4.7 Results

The average Spearman with the CD206 assay was 0.73, ranging from 0.54 to 0.86 per duplicate plate, which indicates a strong correlation between replicates. The control performance demonstrated a clear separation between the positive controls (MRC1_v1, MRC1_v2 and JAK1_v23) and the negative controls. The negative controls performed in the same range as the no virus controls, indicating the absence of a-specific viral effects on the read-out. The cut-off for hit-calling was determined based on the separation between the positive and negative controls. Furthermore, the cut-off was also based on the percentage of CD206 positive cells in M0 macrophages which consisted of −60% CD206 positive cells (FIG. 10A). Based on these parameters a robust Z score cut-off of ≦−3 was chosen. None of the negative controls were identified as a hit and 100% of the MRC1_v1, MRC1_v2 and JAK1_v23 positive controls were identified as a hit.

To eliminate false positive hits due to toxicity, the CTB data was analyzed. The Spearman calculations showed a strong replicate correlation. The average Spearman was 0.82, ranging from 0.70 to 0.93 per duplicate plate. The cut-off for hit-calling was based on the 30% signal reduction level, relative to the no virus control. This corresponded to a Robust Z-score value of −10. As a positive control for toxicity various staurosporin concentrations and the IL4R_v6 virus were used to introduce toxicity. The IL4R_v6 Robust Z scores were lower than the 30% inhibition score of −10 which corresponds with previous obtained data. The addition of various staurosporin concentrations resulted in a dose-respond curve, indicating the sensitivity of the CTB assay (FIG. 10B). Based on these results the cut-off for hit calling was determined to be >−10.

Both, the CD206 screen and the CTB screen were performed successfully based on the Spearman values and the control performance. In total 371 candidate Targets passed the toxicity assay using a cut-off of >−10 (Table 8). From the CD206 screen 73 viruses were identified as a hit with a cut-off of ≦−3. From these 73 confirmed candidate TARGETs, 17 virus constructs were identified as toxic. This resulted in a selection of shRNA constructs against 56 candidate Targets that inhibited the M2 phenotype and classified not to induce toxic effects. These 56 candidate TARGETs were taken forward to the “on target” validation.

TABLE 8 Hit performance in M2 validation and toxicity screen. Cut-off Robust # Source # Average Read-out Z-score plates Hits Spearman CD206  ≦−3 13 73 0.73 (0.54-0.86) CTB >−10 13 371 0.82 (0.70-0.93)

Example 5 “On Target” and Toxicity Assessment of Selected shRNA Constructs 5.1 Background

To exclude that the knockdown constructs have an effect on expression of a different mRNA then the intended mRNA, so called off-target effect, an on target validation was performed with the confirmed candidate Targets. The 56 confirmed candidate TARGETs that passed the screens of Examples 1-3, were selected for the on target validation. To this end, multiple adenoviral-shRNA targeting different sites of the same confirmed candidate Target were designed and tested using the primary screen and the M1 counter screen setup. The confirmed candidate Targets are designated ‘on-target’ if at least two independent shRNA sequences, including the original sequence, pass the criteria of the M2 and M1 validation screens.

The following additional shRNA constructs have been used in “on-target” analysis and demonstrated the ability to inhibit the expression of the target:

5.2 Controls Used in “on Target” Analysis

Two different control panels were used for M1 and M2 differentiation assays as described in Examples 3 and 1 correspondingly.

5.3 Protocol for M2 and M1 “on Target” Screens and Toxicity Assessment

For the on target validation a different virus layout was designed. In that layout the outer wells were omitted and >30% of the plate was filled with negative controls in order to enable hit calling based on negative controls and correction for potential plate effects. Positive controls were included for both the M2 and M1 on target validation. Furthermore, a serial dilution of Staurosporin was added in column one on untransduced cells as reference for the toxicity assay. All adenoviral-shRNAs directed against the candidate TARGETs were randomly distributed over the plate. “No-virus” controls (samples without virus treatment) were positioned on the plates on spots without viruses.

The experimental setup of the M2 and M1 assays (Examples 1 and 3) was adjusted for the “on target” validation. CD14+ cells were isolated as described in Example 1(1.2). On day zero, 5,000 (M2) or 10,000 (M1) CD14+ cells/well were seeded in 384-well culture plates with RPMI Glutamax medium containing 10% FBS, 1% P/S and 100 ng/ml M-CSF. After five days, the M0 macrophages were transduced with the adenoviruses followed by medium refreshment one day later. On day ten the cells were primed with RPMI Glutamax medium containing 10% FBS, 1% P/S and the required cytokines to prime the cells towards M2 (20 ng/ml IL-4 and 20 ng/ml IL-10) or M1 (20 ng/ml INFγ and 5 ng/ml LPS) macrophages. The M1 priming condition was refreshed 16 hours before harvesting the supernatants. On day 13, the M2 and M1 supernatants were harvested and the CTB reagent was added to the cells. CCL18 and TNFα were measured for the M2 and M1 on target validation, respectively. The toxicity was assessed 24 hours after addition of CTB.

5.4 Data Analysis 5.4.1 M2 “on Target” Screen Data Analysis

The B-score analysis was applied to normalize the CCL18 data obtained from the M2 on target screen followed by assessing the replicate performance using the Spearman rank correlation coefficient. The average Spearman correlation for the M2 on target screen was 0.95 indicating a strong correlation between replicates. The control performance demonstrated a clear separation between the positive controls (CCL18_v1, STAT6_v6 and JAK1_v23) and the negative controls. The negative controls performed in the same range as the “no virus” controls. Based on these results a B-score cut-off of ≦−1.6 was used for hit calling.

5.4.2 CTB Assay in M2 “on Target” Screen Data Analysis

The data obtained from the CTB assessment in the M2 on target validation screen was also analyzed using the B-score normalization and Spearman rank correlation. The average Spearman correlation for the M2 CTB screen was 0.89 which indicated a strong correlation between replicates. The cut-off for hit calling was based on the 30% signal reduction level, relative to the no virus controls which corresponded to a B-score value of −8. As a positive control for toxicity various Staurosporin concentrations and the IL4R_v6 virus were used to introduce toxicity. The IL4R_v6 positive control was identified as a hit at a cut-off of −8. The addition of various Staurosporin concentrations resulted in a dose-response curve, indicating that the CTB assay is a sensitive measurement for toxicity. Based on these results the cut-off for hit calling of nontoxic targets in M2 macrophages was set at a B-score of >−8.

5.4.3 M1 “on Target” Screen Data Analysis

The TNFα data derived from the M1 on target screen were also analyzed using the B-score normalization. The average Spearman for M1 on target assay was 0.84 indicating a strong correlation between replicates. The control performance demonstrated a clear separation between two of the positive controls (TNF_v12, TRAF6_v6), whereas TRAF6_v4 and MYD88_v4 showed less inhibition of the TNFα signal. The negative controls showed a small effect compared to the no virus condition, which was also observed in previous M1 assay. This effect is within 25% margin compared to the no virus control and therefore passes the assay criteria. Based on these results a cut-off of >−3 was used for hit calling.

5.4.4 CTB Assay in M1 “on Target” Screen Data Analysis

Based on the CTB read-out of the M1 on target toxicity assay, the B-score was used for normalization and the replicate performance was assessed. The average Spearman for M1 on target assay was 0.83. The cut-off for hit calling was based on the 30% signal reduction level, relative to the no virus control. This corresponded to a B-score value of −8. As a positive control for toxicity various staurosporin concentrations and the IL4R_v6 virus were used to introduce toxicity. The addition of various staurosporin concentrations resulted in a dose-respond curve, indicating the sensitivity of the CTB assay. Based on these results the cut-off for hit calling was determined to be >−8

5.5 Results

When at least two independent shRNA sequences, passed the cut-off criteria of the M2 and M1 “on target” validation screen without observing toxicity, the shRNA was designated as “on target”. Based on these criteria, 14 gene targets were identified as on target Summary of the results is presented in Table 14.

Example 6 M2 and M1 “on Target” Screen Using Different IU and Tox Assessment 6.1 Background

The 34 targets for which the original construct was not identified as hit in Example 5 were retested in a different “on target” screen. The plate layout and the experimental set-up were identical to the “on target” validation in Example 5. The transduction was performed using two source plates, one containing virus constructs with a relatively low IU and one containing virus constructs with a relatively high IU.

6.2 Protocol for M2 and M1 “on Target” Screens

For both the M2 and M1 screens, multiple virus dilutions were made of the two source plates and used to transduce the cells. This was done in such a way that all virus constructs were added at a MOI range of 3-5 for the M2 screens and 6.5-9 for the M1 screens. By doing this, the performance of all virus constructs were more comparable to the performance of the negative and positive controls which were added in a MOI of 4 and 8 for the M2 and M1 assays, respectively.

6.3 Data analysis

Data was normalized using the B-score. For the determination of B scores, negative controls with MOIs comparable to the samples were used. The replicate performance was analyzed using the Spearman correlations and were al >0.4. In all four screens an adequate window was observed between the positive and negative controls. The cut-offs for hit calling were based on the control performance (Table 9).

6.4 Results

When at least two independent shRNA sequences, including the original hit, were confirmed in the screens the target was declared “on target”. In total 13 targets are found to be on target based on the results of the IU based M2 and M1 on target validation and toxicity screens.

TABLE 9 Assay overview IU based on target screens Read-out Spearman COF CCL18 0.82 ≦−3  TNFα 0.67 >−3 M2 CTB 0.79 >−6 M1 CTB 0.74 >−8

When combined with the results of the Example 5, 27 confirmed candidate Targets were designated on target and therefore considered confirmed Targets. These targets were taken forward into further target validation.

Example 7 Analysis of Expression of the TARGETs in Macrophages and BALF 7.1 Background

To confirm mRNA expression of the identified targets in macrophages, mRNA was isolated from these cells to perform whole transcriptome sequencing. To be relevant for fibrotic conditions the TARGETs should be expressed in relevant tissue of the disease. Therefore, in addition to confirm the expression of the TARGETs in patient material alveolar macrophages (AM) were isolated from lung tissue from an IPF patient).

Whole transcriptome sequencing, or mRNA-seq, is a cDNA sequencing application that can be used to profile the entire mRNA population and that enables mapping and quantification of all transcripts. With no probes or primer design needed, mRNA-seq has the potential to provide relatively unbiased sequence information from polyA-tailed RNA for analysis of gene expression, novel transcripts, novel isoforms, alternative splice sites, and rare transcripts in a single experiment, depending on read depth.

7.2 Sample Preparation for the mRNA-Seq Study in Macrophages

To obtain macrophages, buffy coats from two healthy donors, were purchased via the blood bank (Sanquin, The Netherlands) for isolation of PBMCs. The isolation was performed using a Ficoll gradient and subsequently the CD14+ cells were extracted using CD14 MicroBeads (Miltenyi, cat. 130-050-201). After the CD14 isolation a QC regarding the purity was performed on the PBMCs and the isolated CD14+ fraction using flow cytometric analysis.

To differentiate the CD14 positive cells into M0 macrophages, the cells were seeded in 96-well plates with RPMI Glutamax medium, containing 10% FBS, 1% P/S and 100 ng/mL M-CSF. In total four plates were seeded per donor at a cell density of 20,000 cells/well and cultured for six days. On day six, one plate from both donors containing the M0 macrophages were harvested for RNA isolation and the other three plates were refreshed. Ten days after seeding, the second plate from both donors containing M0 macrophages was harvested for RNA isolation. The other two plates from each donor were triggered with 20 ng/mL IFNγ and 5 ng/mL IFNγ or 20 ng/mL IL-10 and 20 ng/mL LPS in RPMI Glutamax medium containing 10% FBS and 1% P/S, to generate M1 or M2, respectively. The cells were cultured for another three days before the macrophages were harvested for RNA isolation. After harvest, specific cell markers were tested using flow cytometry to confirm the M0, M1 and M2 phenotypes. This was done by assessing the expression markers CD163 and CD206. The CD163 and CD206 expression were enhanced in the M2 macrophages and decreased in the M1 macrophages compared to the M0 macrophages, in both donors.

7.4 RNA Determination

Total RNA was isolated from M0 and M2 macrophages as well as AM using a commercially available RNA isolation kit (RNeasy Mini Kit, Qiagen). Concentration and purity was checked using the NanoDrop 2000 (Thermo Scientific).

7.5 mRNA Analysis

The quality and integrity of the RNA sample(s) was analyzed on a RNA 6000 Lab-on-a-Chip using the Bioanalyzer 2100 (Agilent Technologies). Sample quality met the requirements for sample preparation. The Illumina® mRNA-Seq Sample Prep Kit was used to process the samples. The sample preparation was performed according to the Illumina protocol “Preparing Samples for Sequencing of mRNA” (1004898 Rev. D). Briefly, mRNA was isolated from total RNA using the poly-T-oligo-attached magnetic beads. After fragmentation of the mRNA, cDNA synthesis was performed. This was used for ligation with the sequencing adapters and PCR amplification of the resulting product. The quality and yield after sample preparation was measured with a DNA 1000 Lab-on-a-Chip (Agilent Technologies) and all samples passed the quality control. The size of the resulting products was consistent with the expected product with a broad size distribution between 300-600 bp.

7.6 Clustering and DNA Sequencing

Clustering and DNA sequencing using the Illumina HiSeq 2000 (Solexa) were performed according manufacturer's protocols. A total of 6.5 pmol of DNA was used. Two sequencing reads of 100 cycles each using the Read 1 and Read 2 sequencing primers were performed with the flow cell.

7.7 Raw Data Processing

Image analysis, base-calling, and quality check was performed with the Illumina data analysis pipeline RTA v1.13.48 and/or OLB v1.9 and CASAVA v1.8.2. QA analysis performed to evaluate the quality of an Illumina sequencing run was based on quality metrics for a standard run of good quality using the Solexa technology. All lanes of the flow cell passed the QA analysis. Additionally, detailed error rate information based on an Illumina supplied Phi X control was reported. The Phi X control is spiked into the sample in a small amount (up to 5% of the reads). The reads from the Illumina control DNA were removed by the Illumina pipeline during processing of the data. The error rate is calculated after alignment of the reads passing the quality filter to the Phi X reference genome using the ELAND aligner in the Illumina pipeline. All error rates were within the allowed criteria.

7.8 Data Analysis

Reads obtained from the Illumina HiSeq 2000 sequencer were filtered by quality scores with a minimum threshold of Q25 and minimum length of 50 bases. Reads were then aligned to the human reference genome (hg19) with the Bowtie v0.12.7 aligner for each sample. New isoforms were identified with the Cufflinks v2.02 package using default settings and the known transcriptome annotation as mask (Homo _(—) sapiens.GRCh37.65.gff). After new isoform identification for each sample, the newly detected isoforms were merged for all samples and added to the standard transcriptome annotation. Finally, FPKM (Fragments PerKilobase of transcript per Million fragments mapped) values were calculated with Cufflinks for each sample and reported in the default Cufflinks output. The FPKM values are a quantitative representation of the mRNAs in the samples and therefore in the cells used for the mRNA-seq analysis and the screening assays. Highly abundant mRNAs result in high FPKM values whereas low FPKM values represent low copy numbers of the mRNA.

7.9 Sample Preparation for the Expression Study in Alveolar Macrophages from Patient Material

IPF patient tissue sample was obtained from Tissue Solutions. Isolation of alveolar macrophages was performed by adherence on a T80 cell culture flask. Part of the cells was used for flow cytometric analysis to determine the quantity of the macrophage population in this cell preparation. For this, a mouse-anti-human CD68-FITC antibody (Miltenyi, cat. 130-096-964) was used to detect the CD68 expression marker, which is known to be expressed on alveolar macrophages (Kunisch et al, 2004). In total 73% of the gated cells were found to be CD68 positive, representing the macrophage population.

The remainder of the cells were lysed and used for RNA isolation using the RNeasy Mini Kit (Qiagen, cat. 74106). Reverse transcription was performed using the TaqMan® Reverse Transcription Reagents (Applied Bioscience, cat. N8080234) to generate cDNA. This cDNA was quantified on the LightCycler® 480 Real-Time PCR System (Roche Diagnostics) using TaqMan® Fast Advanced Master Mix (Life Technologies, cat. 4444964) with commercially available validated TaqMan® Assays (Life Technologies or Qiagen). A set of four housekeeping genes was tested to confirm the quality of the sample. Roche LightCycler refers to Cp as the cycle number that crosses the threshold, also referred to Ct in other instruments. Bustin et al., 2009) proposes to unify the different nomenclatures to Cq (quantification cycle).

7.10 Results mRNA-Seq

The results of this mRNA-seq analysis are included in Table 12 and were used as selection criteria for the TARGETs. Expression data are listed as FPKM values and used as selection criteria for the TARGETS. Genes were considered to be expressed if FKPM values were determined. The results demonstrate that the TARGETs are expressed in both M0 and M2 macrophages

7.11 Results of qPCR on AM

The results of this analysis are included in Table 15. Expression data are listed as Cq values and used as selection criteria for the TARGETS. Genes were considered to be expressed with Cq values up to 35, C values above 35 were considered as “not expressed”. The results demonstrate that the TARGETs are expressed in AM.

Example 8 Testing siRNA Against the TARGETs in the CCL18 Assay 8.1 Background

To exclude that the shRNA knockdown constructs have an effect on expression of a different mRNA then the intended mRNA, so called off-target effect, an on-target validation was performed with the confirmed candidate Targets using siRNA constructs against selected TARGETS.

8.2 Controls Used in siRNA “on Target” Analysis

siRNA against CCL18, JAK1 and STAT6 were used as positive controls and non-targeting siRNA (Thermo Fisher Scientific Biosciences GMBH) was used as a negative control.

8.3 Protocol for M2 “on Target” siRNA Assay and Toxicity Assessment

The experimental setup was as follows: On day 0 CD14+ 20,000 cells/well were seeded in 96-well plates with RPMI Glutamax medium containing 10% FBS, 1% P/S and 100 ng/ml M-CSF. Five days later the siRNA transfection was preformed. Cells were transfected using 0.02-0.2 μL/well of Dharmafect 1 (Thermo, Cat # T-2001-03). OnTarget Plus siRNA (Thermo Fisher Scientific Biosciences GMBH) in the final concentration of 20 nM were used as smart pools of 4 constructs per well. For EFEMP2 each siRNA construct was also tested individually. One day after cells were primed with RPMI Glutamax medium containing 10% FBS, 1% P/S and the required cytokines to prime the cells towards M2 (20 ng/mL IL-4 and 20 ng/mL IL-10). On day 8 cells the Staurosporin was added to the control wells on each plate (one single row on each plate). On day 9 supernatants were harvested and the CTB reagent was added to the cells. On the same day RNA isolation is performed using standard MagMax Total RNA isolation kit (Ambion, Cat # AM1830) together with Cell Titer Blue assay (Promega, Cat # G808B) as a quality control. The CCL18 is measured in the supernatant using ELISA as described for Example 1.

8.4 Data Analysis

Normalized percentage inhibition (NPI) analysis was used to quantify the effect of siRNA constructs on the read-out. CCL18 siRNA was used as a positive control and non-targeting siRNA as a negative control in the calculations. Normalized percentage inhibition (NPI) was calculated by dividing the difference between sample measurements and the average of positive controls through the difference between positive and negative controls.

Example 9 TARGET Expression in Animal Models of Fibrosis 9.1 Background

To study the expression of the TAREGT genes in vivo, several mouse and rat models of fibrosis were tested and expression in specific tissues like kidney, lung and skin were determined.

9.2 Mouse UUO (Unilateral Ureteral Obstruction) Renal Fibrosis Model

Unilateral ureteral obstruction was performed on Balb/c female mice (from Harlan-France), with 10 mice/group. On day 0, mice were anaesthetized by intra-peritoneal injection and after incision of the skin, the left ureter was dissected out and ligatured with 4.0 silk at two points along its length. The ureter was then sectioned between the 2 ligatures. Intact mice were used as control. Mice were sacrificed by exsanguinations with scissors under anaesthesia after 10 or 21 days.

9.3 Rat ⅚ NTX (⅚ Nephrectomy) Renal Fibrosis Model

Nephrectomy was performed on Sprague-Dawley male rats (from CERJ-France), with 10 rats/group. At DayO, rats were anaesthetized and after incision of the skin, the kidney capsule was removed while preserving the adrenal gland. The renal hilum was ligated and right kidney was removed. The ends of the left kidney are cut with a scalpel resulting in ⅚ nephrectomy. Rats were sacrificed after 4 or 8 weeks.

9.4 Mouse BLM (Bleomycine) Pulmonary Fibrosis Model

Lung fibrosis was induced on CD1 male mice (from CERJ-France) for bleomycin i.v. administration with 6 to 8 mice/group and on C57/B16 J female mice (from Janvier) for bleomycin i.t. administration with 14 mice/group.

For intravenous administration (i.v.) mice were injected intravenously with bleomycin (10 mg/kg; 100 μl/mouse) or saline as a control once per day for the first five consecutive days (Oku et al., 2004). Mice were sacrificed by exsanguinations with scissors under anaesthesia after 3 or 6 weeks.

For intra-peritoneal (i.p) administration mice were anaesthetized by intra-peritoneal injection (under a volume of 10 mL/kg) of anaesthetic solution (18 mL NaCl0.9%+0.5 mL xylazine (5 mg/kg)+1.5 mL ketamine (75 mg/kg)). Bleomycin solution at 2 U/kg or saline was administered by intratracheal route (10 mg/kg; 40 μL/mouse). Mice were sacrificed by exsanguinations with scissors under anaesthesia after 3 weeks.

9.5 Mouse Scleroderma Model (SCL)

Scleroderma was induced on Balb/c female mice (from CERJ-France), with 15 mice per group. On day 0 mice were anesthetised by intra-peritoneal injection of a solution (Xylazine 5 mg/kg, ketamine 75 mg/kg) and shaved. A volume of 100 μl of bleomycin solution at 1 mg/ml or saline was injected subcutaneously with a 26 g needle into the shaved backs of mice. Bleomycin was injected 5 days per week for 3 consecutive weeks. The total experimental period was 6 weeks. Mice were sacrificed by exsanguinations with scissors under anaesthesia after 6 weeks.

9.6 Gene Expression and Regulation in Animal Fibrosis Models

At the end of the in vivo experiment, animals were sacrificed and tissues (½ mouse kidney for UUO model, ⅓ rat kidney for ⅚ NTX model, a piece of skin for mouse scleroderma model and 1 lobe of lung for mouse lung fibrosis model) were collected in 2 ml-microtubes (Ozyme #03961-1-405.2) containing RNALater® stabilization solution (Ambion #AM7021). Tissues were disrupted with 1.4 mm ceramic beads (Ozyme #03961-1-103, BER1042) in a Precellys® 24 Tissue Homogenizer (Bertin Technologies). Total RNA was isolated, subjected to recombinant DNase digestion and purified using Qiazol® (Qiagen #79306) and NucleoSpin® RNA kit (Macherey-Nagel #740955.250) as recommended by the manufacturers. RNA was eluted with 60 μl RNase-free water. RNA concentration and purity were determined by absorbance at 260, 280 and 230 nm cDNA was prepared from 500 ng total RNA by reverse transcription using a high-capacity cDNA RT kit (Applied Biosystems #4368814). 5 μl of 10 times diluted cDNA preparations were used for real-time quantitative PCR. qPCR was performed with gene-specific primers from Qiagen using SYBR Green technology. Reactions were carried out with a denaturation step at 95° C. for 5 min followed by 40 cycles (95° C. for 10 sec, 60° C. for 30 sec) in a ViiA7 real-time PCR system (Applied Biosystems).

The following rodent β-actin primers (Eurogentec) were used: 5′-ACCCTGTGCTGCTCACCG-3′ (forward primer: SEQ ID NO 111) and 5′-AGGTCTCAAACATGATCTGGGTC-3′ (reverse primer SEQ ID NO 112).

Mouse and rat assay mixes are listed in the table below.

TABLE 10 Mouse and rat assay mixes (Qiagen) TARGET Mouse mix Rat mix BPNT1 QT02530745 QT00176540 MS4A4A QT01659476 QT02375744 S1PR2 QT00262773 QT00401884 SLC15A3 QT00139307 QT01080009 USP22 QT01070531 QT02386580 ZMPSTE24 QT01750329 LIF QT00111090 EFEMP2 QT00162134

9.7 Data Analysis

Expression levels of each gene were estimated by their threshold cycle (C_(T)) values in control animals.

The quantification of relative changes in gene expression were expressed using the 2^(−ΔΔC) _(T) method (where ΔΔC_(T)=(C_(T)·target−C_(T)β-actin)_(diseased animal)−(C_(T)·target−C_(T)β-actin)_(control animal). Statistical analysis of 2^(−ΔΔC) _(T) values were performed using unpaired Student's t-test versus control group (***: p<0.001; **: p<0.01; *: p<0.05)

9.8 Results

All tested mRNA are well expressed in fibrotic tissues (kidney, lung and skin) except for MS4A4A which is poorly expressed in kidney (see Table 11)

TABLE 11 mRNA expression levels in intact animals (Ct > 30: low, 25 < Ct < 30: medium, Ct < 25: high) BPNT1 MS4A4A S1PR2 SLC15A3 USP22 EFEMP2 LIF ZMPSTE24 Mouse UUO 20.7 31.1 28.2 28.7 23.1 24.7 30.7 21.8 (10 days) Mouse UUO 19.9 30.4 26.8 27.5 22.5 24.1 29.8 21.3 (21 days) Rat NTX 19.5 >35 24.5 22.4 20.8 — — — (4 week) Rat NTX 20.2 30.4 25.9 22.3 22.6 — — — (8 week) Mouse BLM 23.9 24.9 23.3 23.8 22.6 — — — (i.v. 3 w) Mouse BLM 23.3 23.9 23.6 23.1 22.1 — — — (i.v. 6 weeks) Mouse BLM — 26.1 24.5 24.9 — 23.4 21 24.6 (single i.t.) Mouse SCL 23.1 24.3 25.1 28.3 23.4 25.2 29.5 24.9

Many genes are up or down regulated in mouse UUO model whereas only few regulations were observed in rat NTX model (4 & 8 weeks), and in lung and skin fibrosis models. EFEMP2 and LIF agenes are up regulated in at least one mouse fibrosis model. LIF is strongly upregulated in UUO at both times (10 and 21 days). ZMPSTE24 is significantly downregulated in UUO model at both times (10 and 21 days) (see Table 12)

TABLE 12 qPCR analysis of the fibrosis models (fold >1.8: significant fold induction vs intact animals; fold <−1.8: significant fold inhibition vs intact animals; ns: no significant change; ***: p < 0.001; **: p < 0.01; *: p < 0.05) BPNT1 MS4A4A S1PR2 SLC15A3 USP22 EFEMP2 LIF ZMPSTE24 Mouse −3.5*** 25.2*** 1.6 (***) 2.1*** 1.3 (**) 2.1*** 23.3*** −2.3*** UUO (10 days) Mouse −3.9*** 65.1*** 4.1*** 5.7*** ns 1.7 (***) 14.2*** −3.9*** UUO (21 days) Rat NTX −1.3 (**) ns ns ns −1.3 (**)  — — — (4 week) Rat NTX −1.9 (**) ns 2.5*  −1.6 (*) ns — — — (8 week) Mouse  1.5 (**) ns ns  1.5 (*) ns — — — BLM (i.v. 3 w) Mouse ns ns ns ns ns — — — BLM (i.v. 6 weeks) Mouse −1.2 (*) −1.3 (**)  ns 1.4 (***)  3.3*** ns BLM (single i.t.) Mouse SCL −1.2 (*)  ns ns 2.9*** 1.4 (**) ns 1.6 (*) 1.2 (*)

This table gives an overview of the performance of the 56 candidate Targets that were shown to be on-target. The first column shows the Target gene symbol. Duplicate B-scores are shown for the primary CCL18 screen and rescreen where a cutoff of B-score ≦−1.3 was used. Next to this the M1 TNFα counter screen is shown where a cutoff of ≧−1.3 was used. Results of the M2 CD206 validation assay are shown with duplicate Z-scores where a cutoff of robustZ ≦−3 was used. The M2 CTB toxicity assay is shown with duplicate Z-scores where a cutoff of robustZ >−10 was used to include targets which show no toxicity. The columns on the right show the M2 nuclear count in the M2 CD206 validation assay.

TABLE 13 Overview of the performance of TARGETs in the primary screen, rescreen, M1 counter screen, M2 CD206 validation assay and M2 toxicity assays. Primary CCL18 M1 M2 CD206 CCL18 screen Rescreen counterscreen assay M2 CTB assay M2 nuclei Gene B- B- B- B- B- B- Z- Z- Z- Z- count symbol score 1 score 2 score 1 score 2 score 1 score 2 score 1 score 2 score 1 score 2 Nuclei 1 Nuclei 2 BPNT1 −3.13 −3.21 −2.00 −2.12 −0.84 1.07 −4.14 −4.40 1.12 −1.02 1438 1834 C1RL −2.07 −2.17 −2.03 −1.88 3.68 3.13 −6.17 −5.43 2.78 2.32 1391 1359 DCN −1.33 −1.70 −1.63 −1.78 5.83 2.65 −3.94 −5.15 −3.17 −1.91 1164 1145 EFEMP2 −1.44 −1.42 −1.68 −1.98 −0.22 1.08 −4.10 −4.31 0.50 0.66 1303 1509 EFNB2 −1.93 −1.63 −1.52 −1.64 0.92 −1.23 −3.26 −3.07 −0.03 −0.38 1244 1192 GPR155 −2.68 −1.82 −2.21 −2.34 1.75 1.45 −9.27 −8.54 −1.65 0.82 1158 1431 KCNMB4 −2.32 −2.08 −1.83 −1.67 2.87 2.65 −10.09 −12.84 5.11 0.88 1383 1393 LIF −1.56 −1.39 −1.80 −1.84 10.29 9.83 −3.00 −3.46 −0.94 −1.13 1553 777 MS4A4A −1.61 −1.77 −2.19 −2.18 9.88 6.06 −3.07 −3.75 −0.11 −0.26 1505 1379 RAF1 −2.17 −2.47 −2.11 −2.52 7.43 5.95 −3.28 −3.36 −3.07 −1.68 1407 1390 S1PR2 −3.26 −3.06 −1.87 −2.09 0.49 −1.12 −5.28 −4.97 3.34 0.84 1509 1888 SLC15A3 −2.68 −2.66 −1.84 −2.17 4.56 6.44 −4.88 −3.36 −0.76 −0.77 621 1068 USP22 −3.01 −2.99 −2.11 −2.34 3.97 5.67 −6.05 −4.83 −9.08 −2.26 723 882 ZMPSTE24 −1.92 −1.78 −1.99 −1.96 −0.31 −0.36 −5.42 −6.47 −0.30 1.76 992 1206

This table gives an overview of the performance of the Targets in the on-target assays. The confirmed candidate Target gene symbol and the knock-down sequence of the adenoviral constructs are shown. Results for the shRNAs which were considered a hit are shown. If shRNA was a hit in both OT assays and was an original hit in the primary screen the corresponding values are highlighted in bold. The on-target validation was performed in two batches, A and B. Duplicate results are shown of the M2 CCL18 on-target screen with a cutoff B-score ≦−1.6 for batch A or ≦−3 for batch B. Results of the M1 TNFα counter screen as readout are shown as B-score where non-hits were identified using a cutoff of B-score >−3 for both batches. CTB results are shown for both M2 and M1 assays as duplicate B-scores. Hits were included based on non-toxic effect in the M2 assay if B-score >−8 and in the M1 assay if B-score >−8 (batch A) or B-score >−6 (batch B). On-target indicates if at least 2 independent shRNAs including the original shRNA give the same effect.

TABLE 14 Overview of the performance of the TARGETs in the on-target validation. OT M1 CTB OT M1 counter OT M2 CTB assay SEQ OT M2 screen screen assay B- ID B- B- B- B- B- B- B- score Gene Sequence NO score 1 score 2 score 1 score 2 score 1 score 2 score 1 2 BPNT1 TGAAGCAACCATGCCCATC 64 −13.5 −8.7 −1.2 −0.8 −1.9 −3.6 0.0 0.0 BPNT1 TGTGTTGCTGCTATGAACC 65 −8.4 −9.9 0.3 −2.3 0.4 −3.3 −2.2 −4.9 BPNT1 GAGCTGATTGAAGACAGTC 66 −2.8 −2.0 0.0 3.7 0.2 0.9 1.2 1.0 BPNT1 GTCTTCTTGACAATGTAAC 67 −12.4 −9.2 −0.7 −2.7 −2.4 −4.9 0.6 −0.6 BPNT1 GTACCACAAGGATGTGAAG 68 −5.7 −6.6 5.4 5.4 1.5 −0.5 −2.1 −2.6 C1RL GAATGAGTCCCATAACTTT 69 −3.2 −3.4 −1.2 2.0 −2.6 −2.6 −3.1 −3.3 C1RL CCGTGGCTGTGAACTATAG 70 −4.2 −6.2 −1.1 −1.6 0.2 −0.8 −0.7 −0.4 C1RL GGTCTGTCTGCCCGATAAT 71 −5.9 −4.6 0.5 0.2 −0.2 −0.9 0.1 0.5 C1RL CCAGAGTGTGAATGTGTTC 72 −3.7 −5.6 0.7 −1.7 0.6 −0.6 −1.3 −0.1 C1RL GGTGCTCAGCTATGTGGAC 73 −3.7 −6.5 1.5 7.2 −0.3 −2.9 −3.4 −3.1 DCN GGTTGTCTACCTTCATAAC 74 −5.3 −6.9 4.4 4.9 0.0 −2.1 −0.7 −0.2 DCN GAAGATGAGGCTTCTGGGA 75 −4.9 −6.8 0.4 1.0 2.5 −2.4 3.1 1.6 EFEMP2 CCAAACCTGTGTCAACTTC 76 −5.2 −5.0 1.7 2.0 −2.0 −3.7 −1.1 −1.3 EFEMP2 GAGATGGTCACCATGAATT 77 −8.7 −9.0 2.5 2.0 −0.9 −3.2 −2.0 2.0 EFEMP2 TGATGGTTACCGCAAGATC 78 −4.3 −3.9 −2.0 0.0 −1.0 0.2 2.5 0.6 EFNB2 GCCTATCTATTGGAATTCC 79 −11.8 −7.3 1.8 0.5 −1.0 −1.4 −2.2 −2.0 EFNB2 AATAAAGATCCAACAAGAC 80 −3.0 −3.2 −1.6 −2.6 −0.3 −1.0 −0.9 −0.6 EFNB2 GCCAAACCAGACCAAGATA 81 −6.5 −4.0 4.8 3.1 4.2 1.5 1.2 0.7 GPR155 GATCGAAAGGTACCTGTAT 82 −6.5 −6.3 2.0 3.9 −4.3 −5.1 −0.9 −3.2 GPR155 ATTGGCCTGTTCGCTAATC 83 −2.3 −3.1 0.9 1.8 0.4 −1.0 −0.9 −0.3 GPR155 GAGAGAGGGTACAAATTCC 84 −8.9 −7.2 −0.7 −1.2 −5.4 −4.1 3.0 2.7 GPR155 CCAGAGCTGCATATTAGCC 85 −12.3 −9.7 0.1 1.8 −2.6 −4.9 −3.8 −0.2 KCNMB4 ATTTGTGGTGGGCGTTCTC 86 −4.2 −2.0 −2.2 −2.5 0.6 0.4 −0.4 0.1 KCNMB4 AGAAGCTGTACTCATCGGC 87 −13.3 −10.4 −1.9 −1.7 −0.6 −1.0 −3.8 −3.3 LIF CAACCTCATGAACCAGATC 88 −4.8 −8.0 7.7 10.0 −1.1 −2.8 −1.7 −1.1 LIF CTCGGGTAAGGATGTCTTC 89 −3.4 −2.0 −2.3 −0.4 1.0 1.9 −1.7 −0.2 LIF ACAACCTGGACAAGCTATG 90 −8.2 −8.3 6.7 2.4 −1.4 −5.6 −2.1 −2.5 MS4A4A CCATCACCCTTACTGTAAC 91 −7.8 −7.3 3.0 2.2 −1.0 −4.2 −3.1 −2.8 MS4A4A GCATGGTGCTCCTCTTAAG 92 −7.2 −6.1 2.5 1.9 −4.4 −3.5 −1.0 2.1 RAF1 GTTTGGCAACAGTAAAGTC 93 −16.4 −11.9 7.1 3.1 −3.1 −5.2 −3.3 −5.8 RAF1 GAGGATGCAATTCGAAGTC 94 −11.3 −9.2 7.3 5.9 0.8 −1.8 −1.0 −0.5 RAF1 CCGAATGCAGGATAACAAC 95 −10.0 −7.1 3.0 −2.1 −3.0 −3.0 −3.2 −1.9 RAF1 GCACGCTTAGATTGGAATA 96 −4.8 −5.4 −1.9 −0.9 −3.6 −0.8 0.4 −1.6 S1PR2 CCTGAATTCCCTGCTCAAC 97 −7.6 −7.1 3.4 3.9 −2.4 −1.7 0.7 0.5 S1PR2 GTTCCACTCGGCAATGTAC 98 −6.1 −6.5 3.5 2.9 0.3 1.3 −1.1 −0.4 S1PR2 GTAGCCAATACCTTGCTCT 99 −7.6 −8.9 5.1 6.4 0.2 0.2 1.8 3.3 SLC15A3 GGACTTTGGGAACATCAAC 100 −7.4 −7.2 3.6 −0.1 −4.6 −3.3 −0.6 −3.3 SLC15A3 CCTCGTGCTGTACCTCAAC 101 −8.2 −6.1 6.4 6.1 −7.7 −3.4 2.5 1.5 SLC15A3 CCTCTATGCTTAAGCTCGC 102 −8.5 −9.1 4.2 4.5 −2.4 −4.4 2.7 2.3 SLC15A3 GATGGAGCGCTTACACTAC 103 −4.1 −5.1 4.8 3.6 3.3 3.3 4.4 1.5 USP22 GGACAGTCTCAACAATGAC 104 −7.4 −5.4 1.5 2.8 −3.0 −1.3 −4.8 −5.4 USP22 GCTGTTGTTAACCATCAAG 105 −9.1 −8.1 1.0 0.7 −1.9 −2.1 −5.4 −3.2 USP22 GCTGAAGCACAACCCGAAA 106 −3.3 −4.3 −0.5 −1.5 1.2 0.3 3.7 −0.7 ZMPSTE24 TGGTTGTTCTCAATGTGGC 107 −13.0 −10.5 4.4 2.9 −3.0 −5.4 −1.2 −1.5 ZMPSTE24 GACTGAAGGCACTCTTATT 108 −2.3 −3.7 0.5 0.8 1.8 0.5 −0.1 0.6 ZMPSTE24 GCCATGGAGTCTTTATAAT 109 −6.8 −4.7 3.0 5.8 −1.5 −1.7 −1.8 −2.2

The confirmed candidate Target codes are shown with the corresponding gene class of the Target. Expression data obtained from RNA-seq is shown as an average FPKM value of two healthy donor derived M0 or M2 macrophages. mRNA expression is shown as Ct values (AM=alveolar macrophage, ND=Not Detectable, nt=not tested, AVG=average).

TABLE 15 Overview of the expression of the TARGETS that were confirmed to be on-target by shRNA. RNA seq RNA seq qPCR AM M0 M2 from IPF Gene Gene class (AVG) (AVG) (Ct) BPNT1 Enzyme 15.25 22.48 31.89 C1RL Secreted/Extracellular 0.93 3.29 30.95 DCN Secreted/Extracellular 0.10 0.11 nt EFEMP2 Secreted/Extracellular 0.69 0.41 31.64 EFNB2 Other 0.02 0.03 33.46 GPR155 GPCR 8.94 18.51 30.57 KCNMB4 Ion channel 0.33 0.13 32.46 LIF Secreted/Extracellular 2.98 0.57 31.60 MS4A4A Other 234.68 467.98 23.80 RAF1 Kinase 32.81 24.89 30.45 S1PR2 GPCR 6.05 5.31 29.42 SLC15A3 Transporter 504.20 636.80 27.00 USP22 Enzyme 33.21 31.74 28.15 ZMPSTE24 Enzyme 29.71 26.57 28.75

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1. A method for identifying a compound useful for the treatment of fibrosis, said method comprising: a) contacting a test compound with a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 26-50, fragments and structurally functional derivatives thereof, or with a cell expressing said polypeptide; b) determining a binding affinity of the test compound to said polypeptide, or measuring expression, amount or an activity of said polypeptide; c) contacting the test compound with a population of macrophage cells; d) measuring a property related to differentiation of macrophages into alternatively activated macrophages; and e) identifying a compound capable of reducing or inhibiting macrophage differentiation into alternatively-activated macrophages and demonstrating binding affinity to said polypeptide or reducing or inhibiting the expression, amount or an activity of said polypeptide.
 2. (canceled)
 3. (canceled)
 4. A method for identifying a compound useful for reducing or inhibiting differentiation of macrophages to M2 macrophages, said method comprising: a) contacting a test compound with a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 26-50, functional fragments and functional derivatives thereof or with a nucleic acid encoding an amino acid selected from the group consisting of SEQ ID NOs: 26-50 or a functional derivative thereof; b) measuring the expression or an activity of said polypeptide; c) contacting the test compound with a population of macrophage cells; d) measuring a property related to differentiation of macrophages into alternatively-activated macrophages; and e) identifying a compound capable of reduction or inhibition of differentiation of macrophages into M2 macrophages and inhibiting the expression or an activity of said polypeptide.
 5. (canceled)
 6. The method according to claim 4, wherein the nucleic acid is selected from the group consisting of SEQ ID NOs: 1-25.
 7. The method according to claim 1 or 4, which additionally comprises the step of comparing the compound to be tested to a control.
 8. The method of claim 1 or 4, wherein said polypeptide is coupled to a detectable label.
 9. The method according to claim 1, wherein said polypeptide sequence in steps (a) and (b) is present in an in vitro cell-free preparation.
 10. The method according to claim 1 or 4, wherein said polypeptide sequence in steps (a) and (b) is present in a cell.
 11. The method according to claim 10, wherein the cell naturally expresses said polypeptide.
 12. The method according to claim 10, wherein the cell has been engineered so as to express said polypeptide.
 13. The method of claim 10, wherein said cell is a mammalian cell.
 14. The method of claim 13, wherein said cell is a macrophage cell.
 15. The method of claim 1 or 4, wherein said property is the inhibition of release or expression of a marker of alternatively-activated macrophages.
 16. The method of claim 15 wherein said property is an expression or release of a marker selected from the group consisting of CCL18, CCL13, TGF13, CCL22, CCL17, soluble fibronectin, folate receptor β, CD206, and CD163.
 17. (canceled)
 18. The method according to claim 4 wherein said cells have been triggered by a factor which induces macrophage differentiation into M2 macrophages (M2 inducing factor).
 19. The method according to claim 4, wherein said cells have been triggered by one or more M2 inducing factors selected from the group consisting of IL4, IL10, IL13, immune complexes and lipopolysaccharides.
 20. (canceled)
 21. The method of claim 1 or 4 wherein the method additionally comprises: measuring a property related to the differentiation of macrophages into classically-activated (M1) macrophages and identifying a compound that does not inhibit said differentiation.
 22. The method of claim 21 wherein said property is the level and/or expression of a marker of the M1 macrophage phenotype, and a compound is identified which does not increase the levels of said marker.
 23. The method of claim 22 wherein said marker is TNFα.
 24. The method according to claim 1, wherein said test compound is selected from the group consisting of an antisense polynucleotide, a ribozyme, short-hairpin RNA (shRNA), small interfering RNA (siRNA), and microRNA (miRNA).
 25. The method according to claim 24, wherein said test compound comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1-25.
 26. (canceled)
 27. (canceled)
 28. The method of claim 24, wherein said antisense polynucleotide, said siRNA or said shRNA comprises an antisense strand of 17-25 nucleotides complementary to a sense strand, wherein said sense strand is selected from 17-25 continuous nucleotides of a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1-25.
 29. The method according to claim 1 or 4, wherein said compound is an antibody or an antibody fragment.
 30. A method for treatment of a fibrotic condition in a mammal comprising administering to said mammal a pharmaceutical composition comprising an antibody or a fragment thereof which specifically binds to a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 26-50, or comprising an agent selected from the group consisting of an antisense polynucleotide, a ribozyme, a small interfering RNA (siRNA), microRNA (miRNA) and a short-hairpin RNA (shRNA), wherein said agent comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1-25.
 31. The method according to claim 30 wherein said antibody is a monoclonal antibody.
 32. The method according to claim 30 wherein said antibody is a single chain antibody.
 33. (canceled)
 34. The method according to claim 30, wherein said fibrotic condition is a fibrotic condition associated with differentiation of macrophages into alternatively-activated (M2) macrophages.
 35. The method according to claim 34, wherein said fibrotic condition is selected from idiopathic pulmonary fibrosis (IPF), cystic fibrosis, other diffuse parenchymal lung diseases of different etiologies including iatrogenic drug-induced fibrosis, occupational and/or environmental induced fibrosis, granulomatous diseases (sarcoidosis, hypersensitivity pneumonia), collagen vascular disease, alveolar proteinosis, langerhans cell granulomatosis, lymphangioleiomyomatosis, inherited diseases (Hermansky-Pudlak Syndrome, tuberous sclerosis, neurofibromatosis, metabolic storage disorders, familial interstitial lung disease), radiation induced fibrosis, chronic obstructive pulmonary disease (COPD), scleroderma, bleomycin induced pulmonary fibrosis, chronic asthma, silicosis, asbestos induced pulmonary fibrosis, acute respiratory distress syndrome (ARDS), kidney fibrosis, tubulointerstitium fibrosis, glomerular nephritis, focal segmental glomerular sclerosis, IgA nephropathy, hypertension, Alport syndrome, gut fibrosis, liver fibrosis, cirrhosis, alcohol induced liver fibrosis, toxic/drug induced liver fibrosis, hemochromatosis, nonalcoholic steatohepatitis (NASH), biliary duct injury, primary biliary cirrhosis, infection induced liver fibrosis, viral induced liver fibrosis, autoimmune hepatitis, corneal scarring, hypertrophic scarring, Dupuytren disease, keloids, cutaneous fibrosis, cutaneous scleroderma, systemic sclerosis, spinal cord injury/fibrosis, myelofibrosis, vascular restenosis, atherosclerosis, arteriosclerosis, Wegener's granulomatosis and Peyronie's disease.
 36. (canceled)
 37. An in vitro method of reducing or inhibiting the differentiation of macrophages into alternatively-activated (M2) macrophages, said method comprising contacting a population of mammalian cells comprising macrophage cells with an inhibitor of the activity or expression of a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 26-50.
 38. The method of claim 37 wherein said inhibitor is an antibody.
 39. The method of claim 37 wherein said antibody is a monoclonal antibody.
 40. The method of claim 37 wherein said inhibitor is selected from the group consisting of an antisense polynucleotide, a ribozyme, a small interfering RNA (siRNA), microRNA (miRNA) and a short-hairpin RNA (shRNA), wherein said inhibitor comprises a nucleic acid sequence complementary to, or engineered from, a naturally-occurring polynucleotide sequence of about 17 to about 30 contiguous nucleotides of a nucleic acid encoding said polypeptide. 